IMPORTANT, please read the text below!

The telescopes are operated in the evenings year-round on Friday and Saturday from 7:30 to 10:30 pm. Generally, the observatories are open and volunteers are available to show the telescopes and explain their history and operation even when weather conditions prohibit viewing through the telescopes. The observatories are closed, however, if it is raining or the area outside the observatories is wet.

The telescopes cannot see through thick clouds. Also, to avoid condensation on the telescopes, they are not operated when the humidity is above our limits. Nellie is not operated when the humidity is above 84% and the two refractors do not operate when the humidity exceeds 89%. The current humidity at the observatories is highlighted in bold yellow, below. The normal pattern for humidity at Chabot is for it to reach a minimum in the afternoon and increase over the rest of the day. If you are looking at this in the early evening and the humidity is in the 70’s or low 80’s it is suggested that you wait twenty to thirty minutes and recheck the humidity before deciding whether or not to make the trip.

THE INFORMATION IN THE PARAGRAPH AND TABLE BELOW IS CURRENT AS OF SATURDAY, MARCH 29, 2025 @ 6:40 PM.

Humidity and cloud cover are both potential problems tonight. See the discussion about humidity above, and the current humidity in bold yellow below. Our reflecting telescope, Nellie, is down for maintenance.

TelescopeStatusViewing
Leah – 8″ RefractorMost likely, not operating
Rachel – 20″ RefractorMost likely, not operating
Nellie – 36″ ReflectorNot operatingNot Viewing