7.4 usable nights
4–10 in the middle half of years · 2.3 typically near a dark moon.
347 astronomical-dark hours in an average month
20-year trip-planning baseline
When to plan an observing trip to Capitol Reef National Park
October: 15.8 usable nights on average. A regional planning baseline, not a forecast for your trip.
Site darkness · modelled, not measured
Natural-dark skyBortle classes describe observed sky conditions; this brightness model does not establish a measured Bortle class.21.9–21.9 mag/arcsec²
The short answer
October has been strongest.
It averages 15.8 usable nights, versus 7.4 in January. A typical October lands between 14 and 18 usable nights.
Record2005–2024 · 20 complete years
Usable nightAt least 3 astronomical-dark hours and NASA POWER nighttime cloud ≤30%
Dark-moon nightUsable night with ≤25% illumination at local solar midnight
ResolutionCERES SYN1deg 1° cloud grid; regional climate, not a campsite guarantee
Seasonal fingerprint
Usable nights by month
Month by month
7.7 usable nights
6–10 in the middle half of years · 2.3 typically near a dark moon.
290 astronomical-dark hours in an average month
7.8 usable nights
6–9 in the middle half of years · 2.3 typically near a dark moon.
280 astronomical-dark hours in an average month
8.9 usable nights
5–14 in the middle half of years · 2.5 typically near a dark moon.
236 astronomical-dark hours in an average month
9.9 usable nights
7–13 in the middle half of years · 3.3 typically near a dark moon.
186 astronomical-dark hours in an average month
13.9 usable nights
11–16 in the middle half of years · 4.5 typically near a dark moon.
180 astronomical-dark hours in an average month
9.4 usable nights
5–13 in the middle half of years · 3.4 typically near a dark moon.
186 astronomical-dark hours in an average month
10.8 usable nights
9–14 in the middle half of years · 3.6 typically near a dark moon.
223 astronomical-dark hours in an average month
15.7 usable nights
13–19 in the middle half of years · 5.2 typically near a dark moon.
251 astronomical-dark hours in an average month
15.8 usable nights
14–18 in the middle half of years · 5.4 typically near a dark moon.
308 astronomical-dark hours in an average month
12.8 usable nights
11–14 in the middle half of years · 4.1 typically near a dark moon.
329 astronomical-dark hours in an average month
7.8 usable nights
5–11 in the middle half of years · 2.3 typically near a dark moon.
365 astronomical-dark hours in an average month
Use the baseline honestly
Climate chooses the month. Forecasts choose the night.
The cloud product is a roughly 1° regional grid. It can reveal seasonality, but it cannot know a mountain ridge, valley fog pocket, locked gate, smoke event or the exact sky you will get.
Source: NASA POWER daily data, parameter CLOUD_AMT_NIGHT from the CERES SYN1deg cloud product. GoodSeeing calculates astronomical darkness and lunar illumination independently for each place.