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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.

Excellent conditions
Observing Outlook

Excellent observing conditions expected

Night-window score reflects clouds, rain risk, visibility, dew risk, wind, and humidity. Clouds 74%, rain risk 3%, wind 4 mph.

85/100 Excellent Best: --
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 85 Excellent
Clouds 74% Mostly cloudy
Rain Risk 3% Max overnight
Visibility 15 mi Good
Wind 4 mph Gusts 7 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 4 AM
•
Visual Observing

General sky conditions are available now.

What makes an observing forecast different? →
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Deep Sky Imaging

Add a default rig for tailored guidance.

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

2026-08-24 7 PM → next morning 6 AM
Time Score Outlook Clouds Low Mid High Rain Visibility Dew Spread Wind Humidity
8/24 - 7 PM 89 Excellent 100% 0% 0% 100% 0% 15 mi 13.5°F ? 7 mph 62%
8/24 - 8 PM 91 Excellent 22% 0% 0% 19% 0% 15 mi 12.1°F ? 5 mph 65%
8/24 - 9 PM 91 Excellent 65% 0% 0% 62% 0% 15 mi 11.7°F ? 4 mph 66%
8/24 - 10 PM 91 Excellent 100% 0% 0% 100% 0% 15 mi 11.3°F ? 4 mph 67%
8/24 - 11 PM 91 Excellent 100% 0% 0% 100% 0% 15 mi 11.7°F ? 3 mph 66%
8/25 - 12 AM 79 Good 60% 0% 51% 53% 0% 15 mi 10.8°F ? 4 mph 68%
8/25 - 1 AM 91 Excellent 20% 0% 10% 5% 0% 15 mi 10.4°F ? 4 mph 69%
8/25 - 2 AM 77 Good 98% 0% 97% 5% 3% 15 mi 12.9°F ? 4 mph 63%
8/25 - 3 AM 77 Good 100% 5% 100% 35% 3% 15 mi 14.2°F ? 3 mph 60%
8/25 - 4 AM 92 Excellent 19% 0% 5% 10% 3% 15 mi 12.4°F ? 4 mph 64%
8/25 - 5 AM 76 Good 100% 5% 100% 100% 3% 15 mi 13.3°F ? 3 mph 62%
8/25 - 6 AM 76 Good 100% 5% 100% 68% 3% 15 mi 12.9°F ? 3 mph 63%
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
22% Total
Low
0%
Mid
0%
High
19%
9 PM
65% Total
Low
0%
Mid
0%
High
62%
10 PM
100% Total
Low
0%
Mid
0%
High
100%
11 PM
100% Total
Low
0%
Mid
0%
High
100%
12 AM
60% Total
Low
0%
Mid
51%
High
53%
1 AM
20% Total
Low
0%
Mid
10%
High
5%
2 AM
98% Total
Low
0%
Mid
97%
High
5%
3 AM
100% Total
Low
5%
Mid
100%
High
35%
4 AM
19% Total
Low
0%
Mid
5%
High
10%
5 AM
100% Total
Low
5%
Mid
100%
High
100%
6 AM
100% Total
Low
5%
Mid
100%
High
68%
Why this score?

Limiting Factors

High Clouds 55% High impact
Mid Clouds 39% High impact
Visibility 15 mi Moderate impact
Humidity 65% Moderate impact
Dew Spread 12.3°F Low impact
Source Comparison

Forecast Sources

MVP starts with Open-Meteo; additional sources will improve confidence scoring.
Source Clouds Rain Humidity Wind Status
Open-Meteo 74% 3% 65% 4 mph Primary forecast
Tomorrow.io -- -- -- -- Secondary forecast active
National Weather Service -- -- -- -- Active alert cap: 20