Phoenix Experiences More Winter Rain Than Monsoon Season, NOAA Data Reveals
Contrary to popular belief, Phoenix, Arizona, receives more rainfall during its winter months (December to March) than during the widely recognized monsoon season (June 15 to September 30). Data from the NOAA/NCEI 1991–2020 climate normals indicates that December through March accounts for 46% of the year's rain at Sky Harbor Airport, while the entire monsoon season contributes 34%. This pattern is even more pronounced in the north and east Valley areas, where February often emerges as the wettest month. For instance, Scottsdale Municipal receives 51% of its annual rainfall between December and March. The perception that the monsoon delivers the majority of Phoenix's rain is largely due to its intense, short bursts, which are more noticeable than the slower, soaking rains of winter. The 30-year normals have also shown a slight decrease in annual rainfall for Phoenix, from 8.03 inches in the 1981–2010 period to 7.22 inches in the current 1991–2020 period.