Conditions in Fall and Winter at Mt. Wilson can range from cool to quite cold. Those of you who make regular astronomical observations in California's mountains and deserts will know to bring very warm clothing in layers that can be adjusted for maximum comfort. White flash lights are required outside of the dome at Mt. Wilson for safety reasons, and it is also a good idea to bring a red flashlight for use in the dome.

Although food and drink will be provided, you may want to bring some of your own hot drink as well. You are allowed to sleep inside of the 60-inch dome, so a nice sleeping bag and thick pad will give you good comfort. I have seen people bring lounge chairs to sleep on. Prepare to stay for the night if at all possible.

Bring an overnight bag with any necessities and medication that you require. Asprin is sometimes a good idea to take the edge off the high altitude.