I can't see any ref to surface temp on Wikipedia, but this page: https://nineplanets.org/ceres/ https://nineplanets.org/ceres/ says: > Surface Temperature: -1

I can't see any ref to surface temp on Wikipedia, but this page: https://nineplanets.org/ceres/ https://nineplanets.org/ceres/ says: > Surface Temperature: -105°C but also: > the average surface temperature is about ... minus 38 degrees Celsius