May in Mesa averages a daily high of 35.1°C with nights around 16.1°C. Rain is rare — about 0.9 wet days and 3mm across the month. Generally workable, with some weather to plan around.
Across the year, the best time to visit Mesa is November–March.
Based on TEMPE ASU, AZ US (9.2km), 1995–2024. 23 years of May data.