My bill last month for 2 houses with 4 weeks of 100 degree plus weather was $700, Under Time of Use for the 3 months I was forced to be on it, it5 cost me $200 to have 2 porch lights on in a house we weren’t even living in yet, it was brand new.
Looking at the map, Borrego Springs is in the desert closer to the Salton Sea than it is San Diego. Current weather is ~105F during the day and ~85F for overnight lows. AC is running 24/7..