5.6 usable nights
5–7 in the middle half of years · 1.4 typically near a dark moon.
349 astronomical-dark hours in an average month
20-year trip-planning baseline
Best time to stargaze at Parker
September: 12.7 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.18.9–19.6 mag/arcsec²
The short answer
September has been strongest.
It averages 12.7 usable nights, versus 5.6 in January. A typical September lands between 10 and 15 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
5.7 usable nights
4–8 in the middle half of years · 1.5 typically near a dark moon.
290 astronomical-dark hours in an average month
7.3 usable nights
6–8 in the middle half of years · 1.7 typically near a dark moon.
278 astronomical-dark hours in an average month
7.0 usable nights
4–9 in the middle half of years · 2.0 typically near a dark moon.
230 astronomical-dark hours in an average month
7.4 usable nights
6–9 in the middle half of years · 2.2 typically near a dark moon.
186 astronomical-dark hours in an average month
10.0 usable nights
8–13 in the middle half of years · 3.2 typically near a dark moon.
163 astronomical-dark hours in an average month
8.9 usable nights
7–10 in the middle half of years · 3.2 typically near a dark moon.
181 astronomical-dark hours in an average month
8.5 usable nights
7–10 in the middle half of years · 2.7 typically near a dark moon.
217 astronomical-dark hours in an average month
12.7 usable nights
10–15 in the middle half of years · 4.6 typically near a dark moon.
250 astronomical-dark hours in an average month
11.8 usable nights
10–13 in the middle half of years · 3.5 typically near a dark moon.
307 astronomical-dark hours in an average month
9.3 usable nights
6–12 in the middle half of years · 3.5 typically near a dark moon.
329 astronomical-dark hours in an average month
5.9 usable nights
3–8 in the middle half of years · 1.8 typically near a dark moon.
367 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.