Hayward climate — normals and trends
Hayward (United States) has a warm-summer mediterranean climate (Csb) under the Köppen-Geiger classification. Its mean annual temperature is 14.1 °C and it receives 439 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (19.3 °C on average) and the coldest is January (8.3 °C). Rainfall peaks in January.
Hayward averages 5 frost days, 28 hot days (≥ 30 °C) and 52 rainy days per year.
Hayward has warmed by +1.4 °C between 1940 and 2025, or +0.16 °C per decade. This trend is statistically significant.
The number of frost days there went from about 9 to 1 per year over the period.
The hottest day of the period reached 41.8 °C (on 2 September 2017) and the coldest -6.5 °C (on 22 December 1990).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
HaywardCalifornia
- coords
- 37.67°, -122.08°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
14.1°C
Average daily high
20.4°C
Average daily low
9.0°C
Annual rainfall
439mm
Sunshine / day
10.7h
Mean relative humidity
71%
Average peak wind
14.2km/h
Seasonal range
11.0°C
Frost days (< 0 °C)
5 d/yr
Hot days (≥ 30 °C)
28 d/yr
Rainy days (≥ 1 mm)
52 d/yr
Annual snowfall
0.1 cm
Average feels-like high
19.4 °C
Average feels-like low
7.4 °C
Average peak gust
35.4 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
18.8 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.4 °C
since 1940
+0.2 °C per decade · r² = 0.41 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
41.8 °C
2 September 2017
Coldest day
-6.5 °C
22 December 1990
Wettest day
84 mm
13 October 2009
Windiest day
43.5 km/h
3 December 1983
Strongest gust
118.8 km/h
23 December 1955
Hottest feels-like
43.4 °C
6 September 2022
Coldest feels-like
-10.8 °C
22 December 1990
Snowiest day
3.2 cm
13 March 1975
Sunniest day
14.2 h
29 June 1959
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 15.2 °C | +2.1 °C | 10 mm | -72 mm |
| Feb | 16.1 °C | +1.0 °C | 102 mm | +23 mm |
| Mar | 16.7 °C | 0.0 °C | 70 mm | -2 mm |
| Apr | 19.6 °C | +0.5 °C | 13 mm | -22 mm |
| May | 23.3 °C | +1.4 °C | 2 mm | -13 mm |
| Jun | 23.5 °C | -1.5 °C | 0 mm | -3 mm |
| Jul | 24.2 °C | -2.9 °C | 0 mm | -1 mm |
| Aug | 26.8 °C | -0.1 °C | 1 mm | -0 mm |
| Sep | 26.1 °C | -0.4 °C | 3 mm | -1 mm |
| Oct | 21.9 °C | -1.0 °C | 31 mm | +9 mm |
| Nov | 17.3 °C | +0.1 °C | 69 mm | +19 mm |
| Dec | 13.1 °C | -0.2 °C | 38 mm | -37 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Hayward?
Hayward has a warm-summer mediterranean climate (Köppen Csb). Over 1940-2025, the average annual temperature is 14.1 °C and it receives 439 mm of precipitation per year.
What is the hottest day ever recorded in Hayward?
The hottest day measured in Hayward between 1940 and 2025 was 2 September 2017, reaching 41.8 °C.
What is the coldest day in Hayward?
The coldest day measured in Hayward between 1940 and 2025 was 22 December 1990, at -6.5 °C.
Does it snow in Hayward?
Almost never: Hayward sees virtually no snow, with about 5 frost days per year.
Has the climate of Hayward warmed?
Yes: Hayward warmed by +1.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Hayward?
The wettest day measured in Hayward between 1940 and 2025 was 13 October 2009, with 84 mm of rain in 24 hours.
What was the windiest day in Hayward?
The windiest day measured in Hayward between 1940 and 2025 was 3 December 1983, with winds reaching 43.5 km/h.
What is the warmest month in Hayward?
The warmest month in Hayward is July (19.3 °C on average); the coldest is January (8.3 °C).
How much does it rain in Hayward?
Hayward receives on average 439 mm of precipitation per year, spread over about 52 rainy days.
Is it sunny in Hayward?
Hayward gets on average 10.7 hours of sunshine per day, roughly 3,905 hours per year over 1940-2025.
What is the biggest single-day snowfall in Hayward?
The heaviest 24-hour snowfall measured in Hayward between 1940 and 2025 was 13 March 1975, with 3.2 cm.
Are there tropical nights in Hayward?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Hayward.
What was the most extreme apparent temperature in Hayward?
In Hayward, between 1940 and 2025, the highest apparent temperature reached 43.4 °C on 6 September 2022, and the lowest was -10.8 °C on 22 December 1990.
Compare Hayward with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Hayward