Gilroy climate — normals and trends
Gilroy (United States) has a warm-summer mediterranean climate (Csb) under the Köppen-Geiger classification. Its mean annual temperature is 14.0 °C and it receives 393 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 (19.2 °C on average) and the coldest is January (8.4 °C). Rainfall peaks in January.
Gilroy averages 8 frost days, 19 hot days (≥ 30 °C) and 47 rainy days per year.
Gilroy has warmed by +1.3 °C between 1940 and 2025, or +0.15 °C per decade. This trend is statistically significant.
The number of frost days there went from about 13 to 3 per year over the period.
The hottest day of the period reached 39.8 °C (on 8 September 1944) and the coldest -6.0 °C (on 5 January 1950).
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
GilroyCalifornia
- coords
- 37.01°, -121.57°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
14.0°C
Average daily high
20.2°C
Average daily low
8.8°C
Annual rainfall
393mm
Sunshine / day
10.9h
Mean relative humidity
70%
Average peak wind
11.2km/h
Seasonal range
10.8°C
Frost days (< 0 °C)
8 d/yr
Hot days (≥ 30 °C)
19 d/yr
Rainy days (≥ 1 mm)
47 d/yr
Annual snowfall
0.6 cm
Average feels-like high
19.7 °C
Average feels-like low
7.4 °C
Average peak gust
30.4 km/h
Tropical nights (≥ 20 °C)
1 d/yr
Solar radiation
19.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.3 °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
39.8 °C
8 September 1944
Coldest day
-6.0 °C
5 January 1950
Wettest day
80 mm
13 October 2009
Windiest day
39.2 km/h
22 December 1982
Strongest gust
107.6 km/h
14 February 1986
Hottest feels-like
42.4 °C
4 August 1998
Coldest feels-like
-9.5 °C
5 January 1950
Snowiest day
4.8 cm
4 January 1974
Sunniest day
14.1 h
21 June 1940
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 | 16.1 °C | +2.2 °C | 8 mm | -69 mm |
| Feb | 16.7 °C | +1.3 °C | 95 mm | +20 mm |
| Mar | 16.7 °C | +0.1 °C | 72 mm | +8 mm |
| Apr | 19.0 °C | +0.3 °C | 16 mm | -15 mm |
| May | 22.4 °C | +1.3 °C | 1 mm | -11 mm |
| Jun | 23.1 °C | -1.0 °C | 0 mm | -2 mm |
| Jul | 23.9 °C | -2.5 °C | 0 mm | -1 mm |
| Aug | 26.3 °C | 0.0 °C | 0 mm | -1 mm |
| Sep | 25.2 °C | -0.5 °C | 2 mm | -1 mm |
| Oct | 21.5 °C | -1.1 °C | 30 mm | +13 mm |
| Nov | 18.2 °C | +0.6 °C | 92 mm | +49 mm |
| Dec | 14.9 °C | +0.8 °C | 49 mm | -19 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 Gilroy?
Gilroy has a warm-summer mediterranean climate (Köppen Csb). Over 1940-2025, the average annual temperature is 14.0 °C and it receives 393 mm of precipitation per year.
What is the hottest day ever recorded in Gilroy?
The hottest day measured in Gilroy between 1940 and 2025 was 8 September 1944, reaching 39.8 °C.
What is the coldest day in Gilroy?
The coldest day measured in Gilroy between 1940 and 2025 was 5 January 1950, at -6.0 °C.
Does it snow in Gilroy?
Almost never: Gilroy sees virtually no snow, with about 8 frost days per year.
Has the climate of Gilroy warmed?
Yes: Gilroy warmed by +1.3 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Gilroy?
The wettest day measured in Gilroy between 1940 and 2025 was 13 October 2009, with 80 mm of rain in 24 hours.
What was the windiest day in Gilroy?
The windiest day measured in Gilroy between 1940 and 2025 was 22 December 1982, with winds reaching 39.2 km/h.
What is the warmest month in Gilroy?
The warmest month in Gilroy is July (19.2 °C on average); the coldest is January (8.4 °C).
How much does it rain in Gilroy?
Gilroy receives on average 393 mm of precipitation per year, spread over about 47 rainy days.
Is it sunny in Gilroy?
Gilroy gets on average 10.9 hours of sunshine per day, roughly 3,979 hours per year over 1940-2025.
What is the biggest single-day snowfall in Gilroy?
The heaviest 24-hour snowfall measured in Gilroy between 1940 and 2025 was 4 January 1974, with 4.8 cm.
Are there tropical nights in Gilroy?
Yes: Gilroy has on average 1 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Gilroy?
In Gilroy, between 1940 and 2025, the highest apparent temperature reached 42.4 °C on 4 August 1998, and the lowest was -9.5 °C on 5 January 1950.
Compare Gilroy with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Gilroy