To protect the telescope and avoid calamity, the Observatory must not be opened under any of the following weather conditions:
- Rain, snow, hail, mist, or any form of active precipitation
- Any form of accumulated precipitation (recent rain or snow on the dome)
- Wind GUSTS greater than 25 miles per hour / 40 kilometers per hour
- Daytime (the Sun is extremely bright)
To facilitate checking on these conditions, the Science Center roof has a weather station with live data updated every minute here and a webcam here. For longer term forecasting, you can either use your weather app of choice… or the National Weather Service or ClearDarkSky, two websites that between them include cloud, temperature, and wind forecasts from three different weather models.