Astronomy Conditions Forecast
Astronomy weather conditions: real-time planning tool for stargazers & astrophotographers.
Planning astronomy sessions requires more than just checking if it's cloudy. This astronomy weather conditions dashboard combines relevant meteorological data with seeing calculations to help both beginners and experienced astronomers choose the best time for observation and imaging. Whether stargazing or astrophotography, this free, open source tool provides the forecasting you need.
Just enter your location to get started.
Astronomy Conditions
or
Ratings indicate viewing conditions:
Quick Start Guide
The Astronomy Weather Dashboard provides an easy way to check if conditions are favorable for astronomy and astrophotography at your location. Here's how to use it:
Set Your Location
- Click "Detect My Location" to automatically use your current position
- Or enter a city name, address, or landmark in the search box
- Your selected location will be displayed with coordinates
Check Conditions
- Use the date picker to select any day within the next week
- The time slider lets you see conditions for any hour of the selected day
- Choose between °C and °F temperature display
Understanding the Indicators
- Each condition (Cloud Cover, Seeing, Wind, Humidity) has a color-coded dial
- Green (90-100): Great conditions
- Light Green (80-89): Good conditions
- Yellow (50-79): Marginal conditions
- Red (0-49): Poor conditions
7-Day Overview
- The timeline view shows conditions across the full week
- Each row represents a different metric
- Color coding matches the dials for easy interpretation
- Hover over any time block to see exact values
Privacy Note
The plugin only requests location access when explicitly activated by the user. No location data is stored or transmitted beyond what's needed for immediate weather forecasting.
Technical Details
Grab the source code on GitHub: https://github.com/jagbanana/jg-astro-conditions
Weather Data Source
The plugin uses the Open-Meteo API (api.open-meteo.com) to fetch meteorological data. This free weather API provides:
- Temperature at 2m above ground
- Cloud cover percentage
- Relative humidity
- Dew point temperature
- Wind speed at 10m above ground
Seeing Conditions Calculation
The plugin calculates astronomical seeing conditions using a weighted algorithm that considers multiple factors:
Temperature-Dew Point Spread (30% weight)
- Larger differences between temperature and dew point generally indicate better seeing
- Score improves as the spread increases, up to a maximum beneficial difference
- Helps predict atmospheric stability and moisture content
Wind Speed (30% weight)
- Optimal conditions: 5-10 km/h
- Below 5 km/h: Score reduces (insufficient air mixing)
- Above 10 km/h: Score reduces more sharply (turbulence)
- Above 20 km/h: Poor conditions for observation
Humidity Impact (20% weight)
- Lower humidity generally correlates with better seeing
- Score decreases as humidity increases
- High humidity can indicate potential for dew formation on equipment
Temperature Stability (20% weight)
- Measures the rate of temperature change
- Smaller changes indicate more stable air
- Each degree of change per hour reduces the score
- Rapid temperature changes often indicate unstable air masses
The final seeing score (0-100) combines these factors, providing a comprehensive assessment of likely observing conditions. Values above 80 indicate potentially excellent seeing conditions when combined with clear skies and low humidity.
Additional Features
- Location services use OpenStreetMap's Nominatim API for geocoding
- Data updates automatically when changing location or date
- All calculations are performed client-side for quick response
- Week-long forecasts allow for advance planning of observing sessions