4.8 usable nights
3–6 in the middle half of years · 1.3 typically near a dark moon.
355 astronomical-dark hours in an average month
20-year trip-planning baseline
Best time to stargaze at Owatonna
July: 11.1 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.19.4–20.1 mag/arcsec²
The short answer
July has been strongest.
It averages 11.1 usable nights, versus 2.6 in December. A typical July lands between 9 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
6.1 usable nights
5–8 in the middle half of years · 1.8 typically near a dark moon.
292 astronomical-dark hours in an average month
4.5 usable nights
3–5 in the middle half of years · 1.1 typically near a dark moon.
270 astronomical-dark hours in an average month
4.8 usable nights
3–6 in the middle half of years · 1.2 typically near a dark moon.
210 astronomical-dark hours in an average month
6.1 usable nights
5–6 in the middle half of years · 2.3 typically near a dark moon.
155 astronomical-dark hours in an average month
7.1 usable nights
5–9 in the middle half of years · 2.6 typically near a dark moon.
120 astronomical-dark hours in an average month
11.1 usable nights
9–13 in the middle half of years · 3.8 typically near a dark moon.
134 astronomical-dark hours in an average month
10.0 usable nights
8–11 in the middle half of years · 3.4 typically near a dark moon.
196 astronomical-dark hours in an average month
10.6 usable nights
8–12 in the middle half of years · 3.8 typically near a dark moon.
246 astronomical-dark hours in an average month
8.1 usable nights
6–10 in the middle half of years · 2.9 typically near a dark moon.
304 astronomical-dark hours in an average month
4.7 usable nights
3–6 in the middle half of years · 2.0 typically near a dark moon.
332 astronomical-dark hours in an average month
2.6 usable nights
1–4 in the middle half of years · 0.8 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.