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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 1%, rain risk 17%, wind 5 mph.

86/100 Excellent Best: 3 AM – 6 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 86 Excellent
Clouds 1% Clear
Rain Risk 17% Max overnight
Visibility 12.8 mi Fair
Wind 5 mph Gusts 9 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 5 AM
•
Visual Observing

General sky conditions are available now.

What makes an observing forecast different? →
•
Deep Sky Imaging

Add a default rig for tailored guidance.

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

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Why does focal length change weather sensitivity? →
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Forecast Confidence

High Confidence

Forecast conditions are relatively stable across the night 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

2026-08-22 7 PM → next morning 6 AM
Time Score Outlook Clouds Low Mid High Rain Visibility Dew Spread Wind Humidity
8/22 - 7 PM 83 Excellent 0% 0% 0% 0% 17% 13.4 mi 8°F ? 2 mph 76%
8/22 - 8 PM 82 Excellent 0% 0% 0% 0% 8% 10.3 mi 4.7°F ? 4 mph 85%
8/22 - 9 PM 78 Good 0% 0% 0% 0% 8% 9.5 mi 3.9°F ? 4 mph 87%
8/22 - 10 PM 78 Good 0% 0% 0% 0% 8% 9.6 mi 4°F ? 4 mph 87%
8/22 - 11 PM 83 Excellent 7% 7% 0% 0% 8% 10.8 mi 7.2°F ? 5 mph 79%
8/23 - 12 AM 85 Excellent 5% 5% 0% 0% 8% 11.8 mi 9.7°F ? 6 mph 73%
8/23 - 1 AM 88 Excellent 1% 1% 0% 0% 8% 13.4 mi 11.3°F ? 7 mph 68%
8/23 - 2 AM 88 Excellent 0% 0% 0% 0% 0% 15 mi 9.8°F ? 6 mph 71%
8/23 - 3 AM 91 Excellent 0% 0% 0% 0% 0% 15 mi 11.4°F ? 7 mph 67%
8/23 - 4 AM 91 Excellent 0% 0% 0% 0% 0% 15 mi 11.3°F ? 5 mph 67%
8/23 - 5 AM 92 Excellent 0% 0% 0% 0% 0% 15 mi 11.7°F ? 4 mph 66%
8/23 - 6 AM 92 Excellent 0% 0% 0% 0% 0% 15 mi 11.7°F ? 4 mph 66%
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
0% Total
Low
0%
Mid
0%
High
0%
8 PM
0% Total
Low
0%
Mid
0%
High
0%
9 PM
0% Total
Low
0%
Mid
0%
High
0%
10 PM
0% Total
Low
0%
Mid
0%
High
0%
11 PM
7% Total
Low
7%
Mid
0%
High
0%
12 AM
5% Total
Low
5%
Mid
0%
High
0%
1 AM
1% Total
Low
1%
Mid
0%
High
0%
2 AM
0% Total
Low
0%
Mid
0%
High
0%
3 AM
0% Total
Low
0%
Mid
0%
High
0%
4 AM
0% Total
Low
0%
Mid
0%
High
0%
5 AM
0% Total
Low
0%
Mid
0%
High
0%
6 AM
0% Total
Low
0%
Mid
0%
High
0%
Why this score?

Limiting Factors

Humidity 74% High impact
Visibility 12.8 mi Moderate impact
Dew Spread 8.7°F Moderate impact
Precipitation 17% max 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 1% 17% 74% 5 mph Primary forecast
Tomorrow.io -- -- -- -- Secondary forecast active
National Weather Service -- -- -- -- No severe alert cap