7.0 usable nights
5–10 in the middle half of years · 1.9 typically near a dark moon.
342 astronomical-dark hours in an average month
20-year trip-planning baseline
When to plan an observing trip to Gallup
October: 19.1 usable nights on average. A regional planning baseline, not a forecast for your trip.
Site darkness · modelled, not measured
Brightened skyBortle classes describe observed sky conditions; this brightness model does not establish a measured Bortle class.20.3–20.8 mag/arcsec²
The short answer
October has been strongest.
It averages 19.1 usable nights, versus 6.2 in July. A typical October lands between 16 and 24 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
8.8 usable nights
7–12 in the middle half of years · 2.6 typically near a dark moon.
288 astronomical-dark hours in an average month
11.1 usable nights
8–13 in the middle half of years · 3.4 typically near a dark moon.
285 astronomical-dark hours in an average month
12.8 usable nights
10–14 in the middle half of years · 3.5 typically near a dark moon.
240 astronomical-dark hours in an average month
16.7 usable nights
14–19 in the middle half of years · 5.5 typically near a dark moon.
197 astronomical-dark hours in an average month
16.4 usable nights
14–19 in the middle half of years · 5.8 typically near a dark moon.
180 astronomical-dark hours in an average month
6.2 usable nights
3–8 in the middle half of years · 2.6 typically near a dark moon.
186 astronomical-dark hours in an average month
8.1 usable nights
5–11 in the middle half of years · 2.7 typically near a dark moon.
238 astronomical-dark hours in an average month
16.0 usable nights
14–18 in the middle half of years · 5.8 typically near a dark moon.
254 astronomical-dark hours in an average month
19.1 usable nights
16–24 in the middle half of years · 6.5 typically near a dark moon.
310 astronomical-dark hours in an average month
15.8 usable nights
14–18 in the middle half of years · 5.0 typically near a dark moon.
327 astronomical-dark hours in an average month
6.8 usable nights
5–10 in the middle half of years · 2.1 typically near a dark moon.
360 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.