Arizona, USA · 36.05°N 112.14°W · 2100 m
Stargazing in Grand Canyon
Bortle 2 at 2,100 m, with the summer monsoon as the one thing that can ruin a trip.
- Sky quality
- Bortle 2 — excellent dark sky
- Clear nights a year
- ≈ 187
- Best month overall
- September
- Milky Way core
- March–September
The Milky Way shows structure and casts a faint shadow; the zodiacal light and airglow are visible to the naked eye.
Key facts
- Sky quality
- Bortle 2 — excellent dark skyBortle class 2
- Average clear nights
- 187 per yearNights averaging under 30% cloud, 10-year ERA5 record
- Best Milky Way season
- March–SeptemberPeak month: May, core reaching 25°
- Darkness quality
- Excellent11.2 h of astronomical darkness at its darkest, in December
- Typical cloud cover in July
- 39%44% of nights come in under 30% cloud
- Best month for astrophotography
- OctoberAbout 15.2 dark, moon-free, statistically clear nights
- Coordinates
- 36.0544, -112.14012100 m elevation · America/Phoenix
Questions answered on this page
- Is tonight good for stargazing in Grand Canyon?
- Is the Milky Way visible from Grand Canyon?
- How many clear nights does Grand Canyon get each year?
- What is the best month for astrophotography in Grand Canyon?
- How many hours of true darkness does Grand Canyon get each month?
- How dark is the sky in Grand Canyon on the Bortle scale?
- When is the Milky Way core above the horizon from Grand Canyon?
- Should I drive somewhere darker than Grand Canyon?
The Grand Canyon's South Rim is a certified Dark Sky Park sitting at over two thousand metres, which means thin, dry air and excellent transparency on top of very low light pollution. Aligning the Milky Way core with the canyon itself is one of the most photographed compositions in North American astrophotography, and for good reason.
The complication is the North American monsoon. From early July to mid-September afternoon and evening thunderstorms are frequent, and cloud cover peaks exactly when the galactic core is highest. May, June, late September and October give the best combination of core altitude and clear sky.
Evergreen intelligence
The four questions people ask about Grand Canyon
Computed from 10 years of ERA5 reanalysis at these coordinates and a full year of Sun and Moon geometry — not copied from anywhere.
- How many clear nights does Grand Canyon have?
- About 187 nights a year average less than 30% cloud cover, based on 10 years of ERA5 daily reanalysis at 36.05, -112.14. The clearest month is October at 69% of nights; when you also require darkness and no Moon, roughly 127 nights a year are genuinely usable for faint targets.
- What is the best month for the Milky Way in Grand Canyon?
- May. The galactic centre clears 10° from March to September, and in May it reaches 25° while the sky is astronomically dark, with about 4.5 hours of usable core time a night and 61% of nights averaging under 30% cloud.
- When is it darkest in Grand Canyon?
- December gives the most true darkness — an average of 11.2 hours a night with the Sun more than 18° below the horizon.
- When should I plan an astrophotography trip to Grand Canyon?
- October offers the most nights that are simultaneously dark, moon-free and statistically clear — about 15.2 of them. Book around the new Moon in that month and keep two spare nights; a single fixed date at any location is a coin toss.
Darkness calendar
Grand Canyon month by month
Astronomical darkness and Moon geometry are computed for these coordinates. Cloud figures are ten-year ERA5 daily means. Rating combines darkness, moon-free nights and clear-sky odds.
| Month | Astro darkness | Moon-free dark nights | Avg cloud | Clear nights | Milky Way core | Rating |
|---|---|---|---|---|---|---|
| Jan | 11.0 h | 22 | 48% | 35% | — | Workable |
| Feb | 10.1 h | 21 | 40% | 46% | — | Good |
| Mar | 9.0 h | 20 | 47% | 31% | 21° max | Workable |
| Apr | 7.8 h | 19 | 35% | 48% | 24° max | Good |
| May | 6.4 h | 19 | 30% | 61% | 25° max | Excellent |
| Jun | 5.5 h | 19 | 24% | 69% | 25° max | Excellent |
| Jul | 6.0 h | 19 | 39% | 44% | 25° max | Good |
| Aug | 7.2 h | 19 | 37% | 47% | 25° max | Good |
| Sep | 8.7 h | 19 | 23% | 69% | 20° max | Excellent |
| Oct | 9.8 h | 22 | 23% | 69% | — | Excellent |
| Nov | 10.8 h | 24 | 32% | 57% | — | Good |
| Dec | 11.2 h | 25 | 45% | 41% | — | Good |
"Moon-free dark nights" counts nights with at least two hours of astronomical darkness during which the Moon stays below the horizon. "Clear nights" is the share of days in the ERA5 record averaging under 30% cloud cover.
Practical
What Grand Canyon is actually good for
- Milky Way over the canyon
- High-altitude transparency
- Deep-sky visual
For a decision on a specific night rather than a season, the SnapCosmos Night Engine scores tonight and the next six nights from these coordinates — . The method, weighting and known limits are documented on the Night Engine page, and its measured accuracy is published here.
FAQ
Common questions about the sky in Grand Canyon
- Can you see the Milky Way in Grand Canyon?
- Yes. Grand Canyon sits at Bortle 2 — excellent dark sky, where the Milky Way is an obvious, structured band whenever the galactic centre is above the horizon and the Moon is down.
- When is the best time of year to stargaze in Grand Canyon?
- It depends on what you want to see, and the month-by-month table on this page ranks every month by hours of astronomical darkness, moon-free nights and ten years of cloud statistics for these exact coordinates.
- How dark does it get in Grand Canyon?
- Grand Canyon is at latitude 36.1°N, and this page computes the hours of true astronomical darkness — Sun more than 18° below the horizon — for every month of the year at that latitude.
- Is tonight a good night in Grand Canyon?
- The SnapCosmos Night Engine scores tonight for these coordinates against the coming week using live cloud forecasts, Moon geometry and darkness, and returns a single go, wait or skip recommendation.
Where these numbers come from
- Ten-year cloud-cover climatology and historical night rankingERA5 reanalysisECMWF / Copernicus Climate Change Service
- Hourly cloud cover, precipitation, humidity and visibility forecastsOpen-Meteo forecast and archive APIOpen-Meteo
- Sun, Moon and planet positions, rise and set times, twilight phasesAstronomy Engine (VSOP87 / ELP2000 series)Don Cross, after the IMCCE and JPL analytical theories
- Bortle class and sky-brightness context for each locationWorld Atlas of Artificial Night Sky Brightness (Falchi et al., 2016)Science Advances / Light Pollution Map
- Definitions of civil, nautical and astronomical twilight, and lunar phase conventionsAstronomical Applications DepartmentUnited States Naval Observatory
Figures on this page last recomputed .
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