Two of the hottest places in California in the summer that are well known are Death Valley(usually the hottest) and Palm Springs

Even Palm Springs is supposed to hit 121 degrees this week which also seems early for me too. I've been in Palm Springs at these temperatures up to 122 or 123 degrees before when my son lived there about 10 or more years ago now. When you get out of your car's air conditioning it is sort of like getting into an oven. However, the deserts are usually dry so you can usually survive these temperatures IF you have a car or transportation with air conditioning to keep you from getting heat prostration or a headache. You might have in the desert humidities of 5 to 25 % so it can be survivable up to 130 if you have air conditioning and don't spend much time outside in the peak heats of the day. Most people who work out of doors in these kinds of places work at night when the temperature drops down to 90 degrees to 100 degrees.

I remember being in the Gila Bend area of Arizona doing mining assaying work with my father in 1975. It was getting up to 122 to 125 degrees then where we were. We didn't take a tent with us then and just slept in the back of his open pickup truck because a tent would be too hot with these temperatures then. In the heat of the day I would go to a sulphur spring brought up by a windmill for the wild animals there and soak my t-shirt in the sulphur water and then cool down by driving down dry washes on my Honda 250 dualsport motorcycle then. It kept me from getting heat prostration in these kinds of temperatures. The coolest it got was about 100 degrees at 6 am. The reason we slept in bed of the pickup truck was because of scorpions which were the small ones that are deadly if they sting you near your neck or head. If they sting your arm you can't feel your arm for a few days and the same for your legs.

I got stung by a scorpion in the 1970s at Hapuna Beach before they built the newer hotels there on the Big Island of Hawaii and couldn't walk or use my right leg for a few days after that because my leg was numb from a scorpion bite around 1974 when I lived in Hilo with my wife and baby son then.