2.0 usable nights
1–3 in the middle half of years · 0.3 typically near a dark moon.
355 astronomical-dark hours in an average month
20-year trip-planning baseline
Best time to stargaze at Rexburg
July: 14.8 usable nights on average. Use this seasonal climate baseline to choose a month, then use the live forecast to choose a night.
Site darkness · modelled, not measured
Brightened skyBortle classes describe observed sky conditions; this brightness model does not establish a measured Bortle class.20.9–21.3 mag/arcsec²
The short answer
July has been strongest.
It averages 14.8 usable nights, versus 1.7 in February. A typical July lands between 12 and 17 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
1.7 usable nights
1–3 in the middle half of years · 0.6 typically near a dark moon.
292 astronomical-dark hours in an average month
2.5 usable nights
1–4 in the middle half of years · 0.8 typically near a dark moon.
271 astronomical-dark hours in an average month
3.7 usable nights
2–6 in the middle half of years · 1.4 typically near a dark moon.
211 astronomical-dark hours in an average month
5.0 usable nights
4–7 in the middle half of years · 1.6 typically near a dark moon.
157 astronomical-dark hours in an average month
8.8 usable nights
5–11 in the middle half of years · 3.0 typically near a dark moon.
120 astronomical-dark hours in an average month
14.8 usable nights
12–17 in the middle half of years · 5.2 typically near a dark moon.
136 astronomical-dark hours in an average month
13.9 usable nights
13–16 in the middle half of years · 5.5 typically near a dark moon.
197 astronomical-dark hours in an average month
13.4 usable nights
11–16 in the middle half of years · 4.8 typically near a dark moon.
246 astronomical-dark hours in an average month
7.7 usable nights
6–10 in the middle half of years · 2.1 typically near a dark moon.
304 astronomical-dark hours in an average month
3.6 usable nights
1–6 in the middle half of years · 1.0 typically near a dark moon.
332 astronomical-dark hours in an average month
1.9 usable nights
0–3 in the middle half of years · 0.7 typically near a dark moon.
372 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.