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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 61%, rain risk 0%, wind 5 mph.

91/100 Excellent Best: 7 PM – 9 PM
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 91 Excellent
Clouds 61% Partly cloudy
Rain Risk 0% Max overnight
Visibility 15 mi Good
Wind 5 mph Gusts 11 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 8 PM
•
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

2026-08-23 7 PM → next morning 6 AM
Time Score Outlook Clouds Low Mid High Rain Visibility Dew Spread Wind Humidity
8/23 - 7 PM 92 Excellent 55% 0% 0% 55% 0% 15 mi 23.2°F ? 8 mph 44%
8/23 - 8 PM 93 Excellent 6% 0% 0% 5% 0% 15 mi 20.7°F ? 5 mph 48%
8/23 - 9 PM 93 Excellent 6% 0% 0% 5% 0% 15 mi 19.5°F ? 5 mph 50%
8/23 - 10 PM 93 Excellent 5% 0% 0% 5% 0% 15 mi 16.8°F ? 5 mph 55%
8/23 - 11 PM 89 Excellent 100% 0% 0% 100% 0% 15 mi 14°F ? 5 mph 61%
8/24 - 12 AM 89 Excellent 100% 0% 0% 100% 0% 15 mi 12.6°F ? 5 mph 64%
8/24 - 1 AM 91 Excellent 5% 0% 0% 5% 0% 15 mi 11.7°F ? 5 mph 66%
8/24 - 2 AM 92 Excellent 50% 0% 0% 47% 0% 15 mi 11.2°F ? 4 mph 67%
8/24 - 3 AM 89 Excellent 100% 0% 0% 100% 0% 15 mi 10.7°F ? 5 mph 68%
8/24 - 4 AM 89 Excellent 100% 0% 0% 100% 0% 15 mi 9.9°F ? 4 mph 70%
8/24 - 5 AM 88 Excellent 100% 0% 0% 100% 0% 15 mi 8.7°F ? 3 mph 73%
8/24 - 6 AM 88 Excellent 100% 0% 0% 100% 0% 15 mi 8.5°F ? 2 mph 74%
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
55% Total
Low
0%
Mid
0%
High
55%
8 PM
6% Total
Low
0%
Mid
0%
High
5%
9 PM
6% Total
Low
0%
Mid
0%
High
5%
10 PM
5% Total
Low
0%
Mid
0%
High
5%
11 PM
100% Total
Low
0%
Mid
0%
High
100%
12 AM
100% Total
Low
0%
Mid
0%
High
100%
1 AM
5% Total
Low
0%
Mid
0%
High
5%
2 AM
50% Total
Low
0%
Mid
0%
High
47%
3 AM
100% Total
Low
0%
Mid
0%
High
100%
4 AM
100% Total
Low
0%
Mid
0%
High
100%
5 AM
100% Total
Low
0%
Mid
0%
High
100%
6 AM
100% Total
Low
0%
Mid
0%
High
100%
Why this score?

Limiting Factors

High Clouds 60% High impact
Visibility 15 mi Moderate impact
Humidity 62% Moderate impact
Dew Spread 14°F Low impact
Wind 5 mph 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 61% 0% 62% 5 mph Primary forecast
Tomorrow.io -- -- -- -- Secondary forecast active
National Weather Service -- -- -- -- Active alert cap: 20