Surprise averages 165.5 days a year above 90°F, with February the wettest month at 1.25 in of normal rain. The hottest day on record was 122°F on Jun 26, 1990; the coldest, 20°F on Jan 3, 1970. The single biggest 24-hour rain event recorded was 2.73 in on Aug 24, 1982.
Climate and Average Weather Year Round in Surprise
Year-round temperature
In Surprise, the warmest months are June through September, with average daily highs between 98°F and 105°F. The coldest stretch runs December through February, with highs between 64°F and 69°F and overnight lows reaching 40°F.
Rainfall through the year
Rainfall in Surprise averages 0.7 in per month over the long run. February is the wettest at 1.3 in, while June is the driest at 0.0 in.
Days at 90 °F or hotter
Surprise averages 165.5 days per year at 90 °F or hotter. The hottest year on record saw 188 such days (1999); the coolest just 26 (2026).
Precipitation this year
As of May 29, Surprise has received 0.4 in of precipitation this year — 90% below the long-term normal for this point in the year (3.7 in).