1.4 usable nights
1–1 in the middle half of years · 0.3 typically near a dark moon.
357 astronomical-dark hours in an average month
20-year trip-planning baseline
Best time to stargaze at Pendleton
July: 19.5 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.20.8–21.2 mag/arcsec²
The short answer
July has been strongest.
It averages 19.5 usable nights, versus 1.4 in December. A typical July lands between 18 and 22 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
3.2 usable nights
1–4 in the middle half of years · 0.8 typically near a dark moon.
292 astronomical-dark hours in an average month
3.0 usable nights
1–5 in the middle half of years · 1.1 typically near a dark moon.
268 astronomical-dark hours in an average month
4.8 usable nights
2–6 in the middle half of years · 1.9 typically near a dark moon.
203 astronomical-dark hours in an average month
6.8 usable nights
5–9 in the middle half of years · 2.6 typically near a dark moon.
144 astronomical-dark hours in an average month
9.6 usable nights
7–12 in the middle half of years · 3.4 typically near a dark moon.
103 astronomical-dark hours in an average month
19.5 usable nights
18–22 in the middle half of years · 6.8 typically near a dark moon.
125 astronomical-dark hours in an average month
18.5 usable nights
16–20 in the middle half of years · 6.8 typically near a dark moon.
186 astronomical-dark hours in an average month
13.3 usable nights
11–17 in the middle half of years · 4.5 typically near a dark moon.
245 astronomical-dark hours in an average month
8.3 usable nights
4–11 in the middle half of years · 2.1 typically near a dark moon.
303 astronomical-dark hours in an average month
3.1 usable nights
1–4 in the middle half of years · 0.5 typically near a dark moon.
334 astronomical-dark hours in an average month
1.4 usable nights
0–2 in the middle half of years · 0.1 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.