Most summers it doesn't get past 49C/120F. Parker and Lake Havasu (along the Colorado River) get slightly warmer. 125F is a hot day in Lake Havasu, 128F is the record. Bullhead City (of Airwolf Helicopter fame), gets up into the mid-120's too. Someone who used to live in Parker told me that the water pipes are very close to the surface, so all their showers were hot showers in the summer.
Poll: heat, humidity, or cold?