Arizona has an average annual rainfall of ,[REF] which comes during two rainy seasons, with cold fronts coming from the Pacific Ocean during the winter and a monsoon in the summer [REF].
Indicative of the variation in climate, Arizona is the state which has both the metropolitan area with the most days over 100 °F (Phoenix), and the metropolitan area in the lower 48 states with the most days with a low temperature below freezing (Flagstaff) [REF].