An Excessive Heat Watch (to become a Warning) will cover most of California, a lot of Nevada and Arizona as we hit the Labor Day Weekend. Drink plenty of water, avoid the heat of the day, and never leave a person or pet in a vehicle!
A broad and expansive ridge of high pressure takes control of the forecast, and won't relinquish that control until Tuesday or so next week.
Despite the heat, the dew points should remain around the 50 degree mark or lower during the next few afternoons, so humidity should not be a big problem.
Air Quality will likely deteriorate as we move through the weekend, since high pressure traps Ozone and other pollutants near the surface. The AQI is in the moderate range this morning.
The Labor Day Weekend calls for highs to approach 118, and threaten a few records along the way, so the usual heat precautions apply!