Vietnam After Sunset: Hà Giang Highlands, Coastal Dunes & Rural Mountain Skies
Stargazing in Vietnam changes sharply between the karst ridges of geographic Hà Giang, the open sand horizons of the south-central coast and rural mountain plateaus where fog or forest can matter more than city glow. November–December is used as one shared planning window for a ten-location portfolio, from Bàu Trắng and Mã Pí Lèng to Tà Xùa, Măng Đen, Pù Luông and Nha Trang Observatory. The comparison weighs light escape, recurring cloud risk, atmospheric conditions, astronomical darkness, terrain, access clarity and astronomy support across the ten locations.
Vietnam Night-Sky Planning Map
Coordinates mark broad planning centers across mountain passes, dune fields, the reserve and Nha Trang Observatory rather than parking or after-hours access points. Check the relevant road, gate, reserve or facility rules before traveling at night.
Marker order matches the Location Stargazing Score ranking shown in the cards and comparison table.
Vietnam Stargazing Suitability Score
Vietnam’s score uses the same seven weighted factors across ten locations spanning northern karst roads, south-central dunes, highland plateaus, a forested reserve and one public observatory. It is an editorial planning index, not an official sky classification or live weather forecast. The score does not guarantee clear conditions, open gates or lawful nighttime access at a specific stopping point.
The portfolio scores highest for astronomical darkness and terrain variety, while access certainty, humid-air risk and the lack of verified protection support across most markers pull the total down.
Method Disclosed Editorial Rubric
Raw Comparable point SQM measurements, Bortle classifications and VIIRS radiance values are not available across all ten markers, so official geography, settlement and facility context are scored through the fixed categorical rubric.
Location Scores Bàu Trắng White Dunes 85; Mã Pí Lèng Pass 85; Đồng Văn Karst Plateau 85; Tà Xùa Highland 85; Nam Cương Sand Dunes 70; Măng Đen Plateau 70; Quản Bạ Heaven Gate 70; Red Sand Dunes Mũi Né 55; Pù Luông Nature Reserve 70; Nha Trang Observatory 15
Source Mapping or Location Rationale 85 marks the remote Bàu Trắng, Mã Pí Lèng, Đồng Văn and Tà Xùa planning zones; 70 marks Nam Cương, Măng Đen, Quản Bạ and Pù Luông where settlement or local development is harder to isolate; 55 marks the Mũi Né Red Dunes near the resort corridor; 15 marks urban Nha Trang Observatory.
Median 70/100 across all 10 selected locations.
Period Stable geography, settlement and facility context; categorical light-escape evidence rather than a live night-light layer.
Sources UNESCO: Đồng Văn geopark Vietnam Tourism: dune geography Vietnam tourism authority: Nha Trang Observatory
Method Official Categorical Evidence
Raw Recurring November–December climate descriptions are used as regional proxies. The dry south-central dune belt scores higher; Tà Xùa and Pù Luông carry stronger cloud or mist risk; Nha Trang is penalized because its rainy season runs through September–December.
Location Scores Bàu Trắng White Dunes 85; Mã Pí Lèng Pass 70; Đồng Văn Karst Plateau 70; Tà Xùa Highland 55; Nam Cương Sand Dunes 85; Măng Đen Plateau 70; Quản Bạ Heaven Gate 70; Red Sand Dunes Mũi Né 85; Pù Luông Nature Reserve 55; Nha Trang Observatory 35
Source Mapping or Location Rationale November–December is applied to all ten markers. Regional seasonal climate patterns determine the categorical scores; the values are not point cloud-cover percentages.
Median 70/100 across all 10 selected locations.
Period Preferred Observing Window: November–December; recurring seasonal climate descriptions from the cited regional sources.
Sources Vietnam Tourism: Hà Giang Loop Vietnam Tourism: Bình Thuận Vietnam Tourism: Tà Xùa Vietnam Tourism: Nha Trang
Method Disclosed Editorial Rubric
Raw Comparable point total-column water-vapour values are not available across all ten markers. High mountain interiors receive 70; exposed maritime or humid forest settings receive 55 under the disclosed rubric.
Location Scores Bàu Trắng White Dunes 55; Mã Pí Lèng Pass 70; Đồng Văn Karst Plateau 70; Tà Xùa Highland 70; Nam Cương Sand Dunes 55; Măng Đen Plateau 70; Quản Bạ Heaven Gate 70; Red Sand Dunes Mũi Né 55; Pù Luông Nature Reserve 55; Nha Trang Observatory 55
Source Mapping or Location Rationale Karst and highland sites are treated as moderate-transparency environments with episodic fog; Bàu Trắng, Nam Cương, Red Dunes, Pù Luông and Nha Trang carry more moisture, haze or humid-forest exposure.
Median 62.5/100 across all 10 selected locations.
Period Preferred Observing Window: November–December; recurring moisture, haze and fog context from the cited regional sources.
Sources Vietnam Tourism: Vietnam climate Vietnam Tourism: Bình Thuận Vietnam Tourism: Tà Xùa
Method NOAA Solar-Position Calculation
Raw Bàu Trắng White Dunes (11.06791°N) 9.966 h (61/61 nights); Mã Pí Lèng Pass (23.25000°N) 10.479 h (61/61 nights); Đồng Văn Karst Plateau (23.27700°N) 10.480 h (61/61 nights); Tà Xùa Highland (21.31400°N) 10.402 h (61/61 nights); Nam Cương Sand Dunes (11.57000°N) 9.988 h (61/61 nights); Măng Đen Plateau (14.60146°N) 10.122 h (61/61 nights); Quản Bạ Heaven Gate (23.08950°N) 10.473 h (61/61 nights); Red Sand Dunes Mũi Né (10.95300°N) 9.961 h (61/61 nights); Pù Luông Nature Reserve (20.46653°N) 10.367 h (61/61 nights); Nha Trang Observatory (12.27300°N) 10.020 h (61/61 nights)
Location Scores Bàu Trắng White Dunes 100; Mã Pí Lèng Pass 100; Đồng Văn Karst Plateau 100; Tà Xùa Highland 100; Nam Cương Sand Dunes 100; Măng Đen Plateau 100; Quản Bạ Heaven Gate 100; Red Sand Dunes Mũi Né 100; Pù Luông Nature Reserve 100; Nha Trang Observatory 100
Source Mapping or Location Rationale Each marker latitude is calculated for every night from 1 November through 31 December on the fixed seasonal reference calendar using the Sun-below-minus-18-degree definition. Every marker exceeds the 9-hour normalization ceiling on the 61-night mean, so each receives 100.
Median 100/100 across all 10 selected locations.
Period 1 November–31 December · 61-night seasonal window · 61 expected nights · 61 calculated nights at every marker.
Sources NOAA Solar Calculation Details
Method Fixed Terrain Rubric
Raw Bàu Trắng: low open dunes; Mã Pí Lèng: high pass described at roughly 1,200–1,500 m; Đồng Văn: high karst plateau; Tà Xùa: 1,500–1,800 m; Nam Cương: dunes roughly 20–100 m; Măng Đen: plateau around 1,200 m; Quản Bạ: exposed mountain-gateway terrain; Red Dunes: low open coast; Pù Luông: forested reserve rising to a 1,700 m peak; Nha Trang Observatory: low coastal Hòn Chồng hill.
Location Scores Bàu Trắng White Dunes 85; Mã Pí Lèng Pass 85; Đồng Văn Karst Plateau 70; Tà Xùa Highland 85; Nam Cương Sand Dunes 85; Măng Đen Plateau 70; Quản Bạ Heaven Gate 85; Red Sand Dunes Mũi Né 85; Pù Luông Nature Reserve 50; Nha Trang Observatory 70
Source Mapping or Location Rationale Open dune and ridge horizons score 85; mixed plateau and karst terrain scores 70; Pù Luông scores 50 because forest and valley enclosure can remove large sky sectors.
Median 85/100 across all 10 selected locations.
Period Stable terrain and elevation context from the cited geographic and tourism sources.
Sources UNESCO: Đồng Văn and Mã Pí Lèng Vietnam Tourism: Hà Giang Vietnam Tourism: Tà Xùa Vietnam Tourism: Măng Đen Vietnam Tourism: Pù Luông
Method Fixed Access Rubric
Raw Nha Trang Observatory 85; Măng Đen 70; all other planning zones 50.
Location Scores Bàu Trắng White Dunes 50; Mã Pí Lèng Pass 50; Đồng Văn Karst Plateau 50; Tà Xùa Highland 50; Nam Cương Sand Dunes 50; Măng Đen Plateau 70; Quản Bạ Heaven Gate 50; Red Sand Dunes Mũi Né 50; Pù Luông Nature Reserve 50; Nha Trang Observatory 85
Source Mapping or Location Rationale Nha Trang is a public-facing facility but requires current session confirmation. Măng Đen has clearer public-road and visitor access. The remaining markers are broad landscape zones or road/dune/reserve contexts where an exact legal night stopping point was not verified.
Median 50/100 across all 10 selected locations.
Period Normal access regime; individual gates, roads and observatory sessions can change and should be checked before travel.
Sources Vietnam tourism authority: Nha Trang Observatory VNSC Vietnam Tourism: Măng Đen Vietnam Tourism: Hà Giang Loop
Method Fixed Astronomy-Support Rubric
Raw Nha Trang Observatory 85; the other nine portfolio locations 0.
Location Scores Bàu Trắng White Dunes 0; Mã Pí Lèng Pass 0; Đồng Văn Karst Plateau 0; Tà Xùa Highland 0; Nam Cương Sand Dunes 0; Măng Đen Plateau 0; Quản Bạ Heaven Gate 0; Red Sand Dunes Mũi Né 0; Pù Luông Nature Reserve 0; Nha Trang Observatory 85
Source Mapping or Location Rationale Nha Trang contributes astronomy-support points through its public observatory, 0.5-metre telescope and planetarium infrastructure. The other nine landscape locations do not receive designation points because the cited DarkSky International directory does not list a qualifying designation for them.
Median 0/100 across all 10 selected locations.
Period Standing observatory infrastructure and designation status from the cited facility and certification sources.
Sources Vietnam tourism authority: Nha Trang Observatory VNSC DarkSky International place directory
Weighted Total: 70×0.30 + 70×0.20 + 62.5×0.15 + 100×0.10 + 85×0.10 + 50×0.10 + 0×0.05 = 67.875 → 68/100
Read the Stargazing Suitability Score methodologyTen After-Sunset Planning Locations
Ten distinct observing environments are assessed across northern karst country, south-central dunes, interior plateaus, Pù Luông and Nha Trang.
10 locations shown
Bàu Trắng White Dunes
Bàu Trắng, former Bình Thuận geography · present-day Lâm Đồng · low coastal dune-and-lake system
- White dunes surround the Bàu Trắng freshwater-lake system, giving a broad low-elevation horizon that differs sharply from northern karst valleys.
- The official tourism record places the dune system well away from Phan Thiết’s central urban area, but visitor vehicles and activity can still create local glare.
- November–December falls into the drier, windier part of the former Bình Thuận coastal climate pattern.
- A low or crescent Moon can reveal dune texture while preserving more stellar contrast than a bright Moon.
Main trade-off: Night-use hours and legal stopping points are not established by the tourism material used here. Arrive before sunset, identify a lawful return route, and keep clear of active vehicle areas on the dunes.
Mã Pí Lèng Pass
Mã Pí Lèng, geographic Hà Giang highlands · present-day Tuyên Quang · high pass described at roughly 1,200–1,500 m
- The pass sits in the Đồng Văn karst system between high ridges, with strong relief and long sightlines in selected directions.
- Official sources describe Mã Pí Lèng at roughly 1,200–1,500 metres, depending on the reference and point on the pass, giving it a clear terrain advantage over lowland coastal sites.
- The same exposed road geometry that opens the horizon also brings headlight glare, wind and limited legal stopping space.
- October–December is a common travel window in the Hà Giang highlands, but fog can erase the horizon quickly.
Main trade-off: Treat the marker as a planning center, not a roadside observing instruction. Do not set up on a blind bend, carriageway edge or unconfirmed pull-off; verify road conditions and choose a lawful stopping area before darkness.
Đồng Văn Karst Plateau
Đồng Văn karst highlands · present-day Tuyên Quang · high limestone plateau
- UNESCO describes the geopark as a northern mountainous karst landscape in which limestone covers roughly 60% of the area.
- Karst peaks can shield distant settlement light, yet they also remove large sections of low sky from a valley-floor observer.
- Moving from a town center to a lawful rural edge can matter more than choosing another named viewpoint a few kilometres away.
- The plateau is better treated as a network of observing environments than as one uniform darkness class.
Main trade-off: Village and homestay lighting, fog and road position can change the usable sky over short distances, so conditions vary substantially across the plateau.
Tà Xùa Highland
Tà Xùa, Sơn La · highland band around 1,500–1,800 m
- Vietnam Tourism places the Tà Xùa highland around 1,500–1,800 metres above sea level.
- The area is known for cloud layers and mist; that same cloud behaviour can block astronomical targets even when the regional light environment is favourable.
- Ridge positions can open the horizon above a valley cloud deck, while lower road or settlement positions may sit inside the cloud layer.
- The location is strongest when cloud height, wind and road visibility are checked together rather than assuming elevation guarantees a clear sky.
Main trade-off: Cloud and mist are the main planning risk. Arrive before sunset, avoid unfamiliar ridge roads after visibility falls, and do not use a cloud-hunting viewpoint as proof of unrestricted night access.
Nam Cương Sand Dunes
Nam Cương, former Ninh Thuận geography · present-day Khánh Hòa · dunes roughly 20–100 m
- Nam Cương lies near Phan Rang in one of Vietnam’s notably hot, sunny and dry coastal landscapes.
- Published descriptions put the moving dunes roughly 20–100 metres above sea level, with villages, sea and mountain terrain around the dune field.
- The horizon is more open than a northern valley, but nearby settlement light and maritime moisture can still brighten low sky.
- Moonlight changes the use case: a brighter Moon suppresses faint stars while making dune shape and foreground navigation easier to read.
Main trade-off: The marker is a dune-field planning center, not an overnight access claim. Verify local access and avoid crossing village, agricultural or private land without permission.
Măng Đen Plateau
Măng Đen, former Kon Tum geography · present-day Quảng Ngãi · plateau around 1,200 m
- Măng Đen sits around 1,200 metres and is defined by a cool plateau environment with extensive pine cover.
- Forest can reduce the visible horizon even when the air above the plateau is clear, so open clearings and road geometry matter.
- Town and accommodation lighting create a different night environment from the outer plateau; the score represents a planning zone rather than the town center.
- Public-road access is easier than at several remote northern ridge sites, but individual clearings can have separate land-use rules.
Main trade-off: Pine cover and local lighting can be more limiting than elevation. Use public access, avoid blocking service roads, and verify any forest or attraction gate before planning a late return.
Quản Bạ Heaven Gate
Quản Bạ gateway, geographic Hà Giang highlands · present-day Tuyên Quang · exposed mountain viewpoint terrain
- Quản Bạ is the southern gateway into the Đồng Văn plateau route, where higher road terrain can open wider sky sectors than enclosed valleys.
- The viewpoint geometry is useful for horizon-based photography, but nearby road and settlement lighting weakens the light-escape score versus deeper rural karst areas.
- Mountain fog and low cloud remain relevant even during otherwise favourable cool-season travel periods.
- The map position should be used to compare terrain and light exposure, not as an exact parking instruction.
Main trade-off: Viewing areas near mountain roads require a lawful stopping place. Avoid road shoulders with poor visibility and confirm any gate or viewpoint hours before relying on the site after sunset.
Red Sand Dunes Mũi Né
Mũi Né, former Bình Thuận geography · present-day Lâm Đồng · low coastal dunes near the resort corridor
- The Red Sand Dunes sit much closer to the Mũi Né–Phan Thiết visitor corridor than Bàu Trắng, so local and regional light domes are harder to avoid.
- The open dune horizon remains useful for Moon, planets, bright constellations and landscape work even when faint-sky contrast is reduced.
- Former Bình Thuận’s coast is commonly sunny and windy in the November–April period, while sea haze can still soften the low horizon.
- A nearby bright lamp or vehicle headlight can damage dark adaptation more quickly than a distant city glow.
Main trade-off: Convenience comes with more light and activity. Verify night-use rules, stay clear of vehicle routes, and do not assume a daytime tourist access point remains open after dark.
Pù Luông Nature Reserve
Pù Luông, Thanh Hóa · forested limestone reserve rising toward a 1,700 m peak
- Pù Luông combines forested limestone mountains, villages and narrow valleys rather than one exposed plateau.
- The reserve rises toward a 1,700-metre peak, but a high summit figure does not describe the elevation or horizon at every village or road point.
- Forest and valley walls can block large sectors of sky while also shielding some distant artificial light.
- December can bring northern cold spells, and the reserve’s local roads and protected-area rules require more checking than an urban astronomy facility.
Main trade-off: The broad marker is not a night-trail recommendation. Check reserve rules, accommodation access and the return route; avoid entering forest tracks or private village land simply to gain a darker horizon.
Nha Trang Observatory
Hòn Chồng, Nha Trang, Khánh Hòa · low coastal urban observatory site
- Nha Trang Observatory is a public-facing astronomy facility at Hòn Chồng with a 0.5-metre optical telescope and planetarium infrastructure.
- Its urban coastal position gives it the weakest artificial-light escape in the portfolio, which is useful as a contrast with remote dunes and highlands.
- Nha Trang’s rainy season runs from September to December, so the shared November–December window is less reliable here than at the drier dune sites.
- Facility access is session-based rather than independent field access; current ticketing and observing schedules should be checked with the operator.
Main trade-off: Do not enter observatory compounds outside visitor arrangements. This marker represents the facility context, not an unrestricted observing pad, and weather can cancel practical viewing even when a session is scheduled.
Hà Giang Karst After Dark: Valley Shielding, Ridge Exposure and Road Light
Đồng Văn, Mã Pí Lèng and Quản Bạ do not produce the same usable sky even when they sit inside the same broad highland system. UNESCO describes the Đồng Văn landscape as heavily karstic, with limestone covering about 60% of the geopark. In a narrow valley, those limestone walls can hide distant settlement glow while cutting away the low horizon. On an exposed pass, the horizon opens but headlights, wind and fog become harder to ignore.
Đồng Văn valley positions
Useful when surrounding relief blocks a distant light dome. Less useful for low-altitude objects, broad meteor watching or compositions that need an uninterrupted horizon.
Mã Pí Lèng ridge positions
More sky can be visible above the karst, but the road itself is not an observing platform. A legal stopping place away from traffic matters more than the exact marker coordinate.
Quản Bạ gateway positions
Easier approach does not mean darker conditions. Nearby settlement and road light can be more noticeable here than deeper in the plateau.
Vietnam’s 2025 provincial reorganization changed several administrative labels associated with these locations. The former Hà Giang province is now within Tuyên Quang; former Bình Thuận is within Lâm Đồng; former Ninh Thuận is within Khánh Hòa; and former Kon Tum is within Quảng Ngãi. Geographic names used in tourism and heritage material still remain useful for identifying these landscapes. Government of Vietnam administrative reorganization record.
Bàu Trắng, Nam Cương and Mũi Né: Open Horizons, Different Light Domes
Vietnam’s coastal dunes solve the horizon problem better than the northern karst, but they introduce a different set of constraints. Bàu Trắng sits farther from the Phan Thiết urban core, Nam Cương combines dunes with nearby villages and mountain edges, and the Red Sand Dunes are close to the Mũi Né visitor corridor. None should be treated as a measured dark-sky reserve.
| Dune system | Horizon use | Light pattern | Night-weather issue | Moonlight use |
|---|---|---|---|---|
| Bàu Trắng | Broad, low horizon around dunes and lakes | Remote relative to Phan Thiết, with local visitor lights possible | Wind and maritime haze | Useful for revealing sand relief without relying on artificial foreground light |
| Nam Cương | Open dune sectors with village and mountain edges | Regional settlement glow more plausible than at a remote desert core | Moist coastal air and moving sand | Good for dune shape; bright phases reduce faint-star contrast |
| Red Sand Dunes Mũi Né | Open but close to developed coast | Strongest resort-corridor influence of the three | Haze, wind and traffic/activity light | Often better suited to Moon, planets and landscape work than faint-sky hunting |
Official tourism material places Bàu Trắng roughly 65 km northeast of Phan Thiết, while the Red Sand Dunes sit much closer to the city and Mũi Né corridor. Bàu Trắng’s greater distance from Phan Thiết reduces regional glow, but entrance lighting, vehicle staging areas and roadside businesses can still affect dark adaptation.
Tà Xùa, Măng Đen and Pù Luông: Cloud, Forest and Horizon Limits
Tà Xùa, Măng Đen and Pù Luông show why elevation cannot stand in for observing quality. Tà Xùa is an elevated cloud-hunting landscape around 1,500–1,800 metres. Măng Đen is a roughly 1,200-metre plateau with extensive pine cover. Pù Luông combines forest, limestone and enclosed valleys below a reserve landscape rising toward a 1,700-metre peak.
Tà Xùa: cloud deck first
A ridge can sit above a valley cloud layer, yet the same night may put the road or observing position inside mist. Cloud height and road visibility deserve the same attention as the star forecast.
Măng Đen: tree line first
Pine forest can remove horizon sectors without adding much artificial light. An open public clearing can outperform a higher but enclosed forest position.
Pù Luông: valley walls first
Village valleys can shield regional glow but reduce sky area. Reserve rules, forest tracks and accommodation access need checking before a late-night plan.
A dark-looking rural location can still be a poor astronomy location when cloud, tree cover or valley walls remove the sky. Conversely, a slightly brighter open ridge can be better for meteors or horizon targets when access is lawful and the weather is stable.
Moonlight Choices for Vietnam’s Dunes and Karst
New Moon: star contrast
Best suited to faint Milky Way structure, dense star fields and meteor work. Dunes and karst foregrounds can become nearly black without a separate low-impact foreground-light plan.
Crescent or low Moon: balance
Often the strongest compromise for Bàu Trắng or Nam Cương: enough natural side light to reveal sand texture while leaving much of the sky darker than under a bright Moon.
Bright Moon: landscape priority
Faint stars lose contrast, but dune ridges, karst silhouettes and walking surfaces become easier to read. The night can still work well for Moon, planets and landscape photography.
The human eye will not show the same colour and intensity recorded by a long camera exposure. A camera can accumulate faint light for seconds; dark-adapted vision sees the Milky Way more like a pale structured band. Keeping phone screens and white headlights low matters more at the remote sites than adding another kilometre of travel after a good dark position has already been found.
Vietnam After-Sunset Location Comparison
The table follows the same score order as the map and location cards. Each value comes from the disclosed seven-factor planning method and should not be read as a direct sky-brightness measurement.
| Rank | Location | Score | Light Escape | Clear Sky | Horizon | Access | Best Use | Main Constraint |
|---|---|---|---|---|---|---|---|---|
| 1 | Bàu Trắng White Dunes | 74/100 | 85 | 85 | 85 | 50 | Wide-horizon stars and moonlit dune photography | Maritime haze, wind and uncertain night-use points |
| 2 | Mã Pí Lèng Pass | 74/100 | 85 | 70 | 85 | 50 | Karst silhouettes and high-ridge photography | Road exposure, fog and headlight interruption |
| 3 | Đồng Văn Karst Plateau | 72/100 | 85 | 70 | 70 | 50 | Remote karst sky with shielded light sectors | Broken horizon and highly local lighting |
| 4 | Tà Xùa Highland | 71/100 | 85 | 55 | 85 | 50 | Ridge sky and layered mountain foregrounds | Mist, cloud deck and road visibility |
| 5 | Nam Cương Sand Dunes | 70/100 | 70 | 85 | 85 | 50 | Open-horizon dune composition and stars | Village light, maritime moisture and access clarity |
| 6 | Măng Đen Plateau | 70/100 | 70 | 70 | 70 | 70 | Accessible highland sky with forest foregrounds | Tree obstruction and growing local light |
| 7 | Quản Bạ Heaven Gate | 69/100 | 70 | 70 | 85 | 50 | Accessible karst horizon and landscape work | Road lights, fog and uncertain late access |
| 8 | Red Sand Dunes Mũi Né | 65/100 | 55 | 85 | 85 | 50 | Easy dune foregrounds, Moon and bright-sky targets | Resort-corridor light and maritime haze |
| 9 | Pù Luông Nature Reserve | 60/100 | 70 | 55 | 50 | 50 | Shielded rural mountain atmosphere | Forest obstruction, valley enclosure and cold-season cloud |
| 10 | Nha Trang Observatory | 50/100 | 15 | 35 | 70 | 85 | Public telescope and astronomy interpretation | Urban light and September–December rain |
Tonight’s Astronomical Darkness
Calculated live from each location’s coordinates using NOAA’s public solar-position formula. Weather, cloud cover and local obstructions are not included.
Calculating…
Score Verification and Limitations
Preferred Observing Window
November–December
Locations Assessed
10
Method Version
2.2
Comparability Quality
C
Score Scope
Selected Location Portfolio
Principal Data Periods
Recurring November–December climate context, stable terrain and access evidence, and the 1 November–31 December fixed seasonal reference calendar for astronomical darkness.
Limitations
Artificial-light escape, clear-sky reliability, atmospheric transparency and access rely partly on categorical evidence rather than uniform point measurements. Comparable SQM, VIIRS radiance, cloud-percentage and water-vapour measurements are not available across all ten markers.