Hayward averages 9 days a year above 90°F, with December the wettest month at 3.2 in of normal rain. The hottest day on record was 108°F on Sep 2, 2017; the coldest, 27°F on Dec 23, 1998. The single biggest 24-hour rain event recorded was 4.34 in on Dec 31, 2022.
Climate and Average Weather Year Round in Hayward
Year-round temperature
In Hayward, the warmest months are June through September, with average daily highs between 74°F and 77°F. The coldest stretch runs December through February, with highs between 59°F and 62°F and overnight lows reaching 43°F.
Rainfall through the year
Rainfall in Hayward averages 1.3 in per month over the long run. December is the wettest at 3.2 in, while July is the driest at 0.0 in.
Days at 90 °F or hotter
Hayward averages 9.0 days per year at 90 °F or hotter. The hottest year on record saw 20 such days (2020); the coolest just 1 (2018).
Precipitation this year
As of May 28, Hayward has received 11.5 in of precipitation this year — 14% above the long-term normal for this point in the year (10.1 in).