4.6 usable nights
2–8 in the middle half of years · 1.8 typically near a dark moon.
310 astronomical-dark hours in an average month
20-year trip-planning baseline
Best time to stargaze at Jupiter
May: 9.1 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
Bright skyBortle classes describe observed sky conditions; this brightness model does not establish a measured Bortle class.19.3–20.0 mag/arcsec²
The short answer
May has been strongest.
It averages 9.1 usable nights, versus 4.3 in June. A typical May lands between 6 and 13 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
7.5 usable nights
5–10 in the middle half of years · 2.5 typically near a dark moon.
283 astronomical-dark hours in an average month
8.2 usable nights
5–11 in the middle half of years · 3.1 typically near a dark moon.
300 astronomical-dark hours in an average month
7.5 usable nights
6–9 in the middle half of years · 2.6 typically near a dark moon.
243 astronomical-dark hours in an average month
9.1 usable nights
6–13 in the middle half of years · 2.7 typically near a dark moon.
248 astronomical-dark hours in an average month
4.3 usable nights
2–5 in the middle half of years · 1.8 typically near a dark moon.
235 astronomical-dark hours in an average month
5.0 usable nights
2–8 in the middle half of years · 1.8 typically near a dark moon.
246 astronomical-dark hours in an average month
4.4 usable nights
1–7 in the middle half of years · 1.6 typically near a dark moon.
248 astronomical-dark hours in an average month
4.4 usable nights
2–6 in the middle half of years · 1.3 typically near a dark moon.
273 astronomical-dark hours in an average month
7.0 usable nights
4–9 in the middle half of years · 2.1 typically near a dark moon.
310 astronomical-dark hours in an average month
4.6 usable nights
3–6 in the middle half of years · 1.2 typically near a dark moon.
315 astronomical-dark hours in an average month
6.0 usable nights
3–8 in the middle half of years · 2.3 typically near a dark moon.
317 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.