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Night Forecast

Weather
Observing Conditions.

Hour-by-hour night-window forecast built for observing, imaging, and planning around clouds, rain risk, visibility, dew spread, wind, humidity, and your active rig.

Good conditions
Observing Outlook

Good observing conditions expected

Night-window score reflects clouds, rain risk, visibility, dew risk, wind, and humidity. Clouds 88%, rain risk 17%, wind 6 mph.

72/100 Good Best: 9 PM – 12 AM
Choose Forecast Date
Su M T W Th F Sa
16 17 18 19 20 21 22 23 24 25 26 27 28 29
Forecast Location Chicago Area 41.878100, -87.629800 41.87810, -87.62980
Overall 72 Good
Clouds 88% Overcast
Rain Risk 17% Max overnight
Visibility 13.8 mi Fair
Wind 6 mph Gusts 15 mph
Observatory Intelligence

No default rig selected

Add your telescope, focal length, and mount to unlock equipment-specific weather guidance.

Ephemeris can interpret wind, cloud layers, humidity, and dew risk differently for widefield, mid-focal, and long-focal-length setups.

Best Use Tonight General observing guidance
Avoid Tonight Rig-specific guidance unavailable
Improves After 7 PM
•
Visual Observing

General sky conditions are available now.

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Deep Sky Imaging

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Why does rig data matter for imaging? →
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Planetary / Lunar

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Why does focal length change weather sensitivity? →
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Forecast Confidence

Moderate Confidence

The forecast is usable, but cloud timing or moisture may change the practical observing window.

3 forecast source active
  • Forecast sources active: 2
  • Alert sources active: 1
  • Forecast models disagree during multiple observing hours
  • Cloud cover changes sharply during the night
Hour-by-Hour

Observing Window

2026-08-25 7 PM → next morning 6 AM
Time Score Outlook Clouds Low Mid High Rain Visibility Dew Spread Wind Humidity
8/25 - 7 PM 91 Excellent 100% 0% 0% 100% 4% 15 mi 16.8°F ? 7 mph 56%
8/25 - 8 PM 87 Excellent 100% 0% 0% 100% 9% 15 mi 13.3°F ? 7 mph 63%
8/25 - 9 PM 87 Excellent 71% 0% 0% 65% 9% 15 mi 11.6°F ? 6 mph 67%
8/25 - 10 PM 84 Excellent 70% 0% 5% 68% 9% 15 mi 9.9°F ? 6 mph 71%
8/25 - 11 PM 84 Excellent 75% 0% 5% 60% 9% 15 mi 8.7°F ? 6 mph 74%
8/26 - 12 AM 76 Good 42% 0% 5% 36% 9% 5.6 mi 6.8°F ? 7 mph 79%
8/26 - 1 AM 65 Good 100% 0% 100% 100% 9% 13 mi 4°F ? 4 mph 87%
8/26 - 2 AM 60 Fair 100% 0% 100% 100% 17% 13.6 mi 3.3°F ? 5 mph 89%
8/26 - 3 AM 60 Fair 100% 0% 87% 100% 17% 14.2 mi 3.3°F ? 6 mph 89%
8/26 - 4 AM 60 Fair 100% 2% 79% 100% 17% 14.8 mi 3°F ? 7 mph 90%
8/26 - 5 AM 55 Fair 100% 7% 87% 96% 17% 14.9 mi 2.3°F ? 7 mph 92%
8/26 - 6 AM 52 Fair 100% 13% 99% 90% 17% 14.9 mi 1.7°F ? 7 mph 94%
Cloud Timeline

Cloud Cover by Hour

Each hour shows total cloud cover plus the split between low, mid, and high cloud layers.

Low Mid High
7 PM
100% Total
Low
0%
Mid
0%
High
100%
8 PM
100% Total
Low
0%
Mid
0%
High
100%
9 PM
71% Total
Low
0%
Mid
0%
High
65%
10 PM
70% Total
Low
0%
Mid
5%
High
68%
11 PM
75% Total
Low
0%
Mid
5%
High
60%
12 AM
42% Total
Low
0%
Mid
5%
High
36%
1 AM
100% Total
Low
0%
Mid
100%
High
100%
2 AM
100% Total
Low
0%
Mid
100%
High
100%
3 AM
100% Total
Low
0%
Mid
87%
High
100%
4 AM
100% Total
Low
2%
Mid
79%
High
100%
5 AM
100% Total
Low
7%
Mid
87%
High
96%
6 AM
100% Total
Low
13%
Mid
99%
High
90%
Why this score?

Limiting Factors

High Clouds 85% Major limiter
Humidity 79% Major limiter
Dew Spread 7.1°F High impact
Mid Clouds 47% High impact
Visibility 13.8 mi Moderate impact
Source Comparison

Forecast Sources

MVP starts with Open-Meteo; additional sources will improve confidence scoring.
Source Clouds Rain Humidity Wind Status
Open-Meteo 88% 17% 79% 6 mph Primary forecast
Tomorrow.io -- -- -- -- Secondary forecast active
National Weather Service -- -- -- -- Active alert cap: 20