Porterville climate — normals and trends
Porterville (United States) has a hot-summer mediterranean climate (Csa) under the Köppen-Geiger classification. Its mean annual temperature is 17.3 °C and it receives 478 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 (27.5 °C on average) and the coldest is January (8.9 °C). Rainfall peaks in March.
Porterville averages 5 frost days, 100 hot days (≥ 30 °C) and 59 rainy days per year.
Porterville has warmed by +2.4 °C between 1940 and 2025, or +0.28 °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 43.9 °C (on 16 August 2020) and the coldest -11.2 °C (on 23 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
PortervilleCalifornia
- coords
- 36.07°, -119.02°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
17.3°C
Average daily high
23.3°C
Average daily low
11.6°C
Annual rainfall
478mm
Sunshine / day
11.2h
Mean relative humidity
58%
Average peak wind
9.6km/h
Seasonal range
18.6°C
Frost days (< 0 °C)
5 d/yr
Hot days (≥ 30 °C)
100 d/yr
Rainy days (≥ 1 mm)
59 d/yr
Annual snowfall
0.8 cm
Average feels-like high
23.1 °C
Average feels-like low
10.0 °C
Average peak gust
24.4 km/h
Tropical nights (≥ 20 °C)
44 d/yr
Solar radiation
19.6 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.4 °C
since 1940
+0.3 °C per decade · r² = 0.57 · 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
43.9 °C
16 August 2020
Coldest day
-11.2 °C
23 December 1990
Wettest day
82 mm
6 December 1966
Windiest day
31.1 km/h
1 March 1983
Strongest gust
69.1 km/h
4 January 2008
Hottest feels-like
47.0 °C
4 July 1991
Coldest feels-like
-15.4 °C
23 December 1990
Snowiest day
4.8 cm
20 December 1968
Sunniest day
14.0 h
23 May 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 | 14.7 °C | +0.6 °C | 23 mm | -58 mm |
| Feb | 17.6 °C | +1.9 °C | 95 mm | +12 mm |
| Mar | 17.4 °C | -0.2 °C | 139 mm | +50 mm |
| Apr | 21.3 °C | +0.6 °C | 28 mm | -21 mm |
| May | 27.3 °C | +2.0 °C | 1 mm | -18 mm |
| Jun | 32.8 °C | +2.5 °C | 0 mm | -4 mm |
| Jul | 34.6 °C | +0.2 °C | 0 mm | -1 mm |
| Aug | 36.0 °C | +2.3 °C | 0 mm | -1 mm |
| Sep | 31.8 °C | +1.2 °C | 13 mm | +7 mm |
| Oct | 23.9 °C | -0.8 °C | 60 mm | +39 mm |
| Nov | 19.1 °C | +0.9 °C | 98 mm | +47 mm |
| Dec | 15.5 °C | +1.3 °C | 57 mm | -16 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 Porterville?
Porterville has a hot-summer mediterranean climate (Köppen Csa). Over 1940-2025, the average annual temperature is 17.3 °C and it receives 478 mm of precipitation per year.
What is the hottest day ever recorded in Porterville?
The hottest day measured in Porterville between 1940 and 2025 was 16 August 2020, reaching 43.9 °C.
What is the coldest day in Porterville?
The coldest day measured in Porterville between 1940 and 2025 was 23 December 1990, at -11.2 °C.
Does it snow in Porterville?
Almost never: Porterville sees virtually no snow, with about 5 frost days per year.
Has the climate of Porterville warmed?
Yes: Porterville warmed by +2.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Porterville?
The wettest day measured in Porterville between 1940 and 2025 was 6 December 1966, with 82 mm of rain in 24 hours.
What was the windiest day in Porterville?
The windiest day measured in Porterville between 1940 and 2025 was 1 March 1983, with winds reaching 31.1 km/h.
What is the warmest month in Porterville?
The warmest month in Porterville is July (27.5 °C on average); the coldest is January (8.9 °C).
How much does it rain in Porterville?
Porterville receives on average 478 mm of precipitation per year, spread over about 59 rainy days.
Is it sunny in Porterville?
Porterville gets on average 11.2 hours of sunshine per day, roughly 4,088 hours per year over 1940-2025.
What is the biggest single-day snowfall in Porterville?
The heaviest 24-hour snowfall measured in Porterville between 1940 and 2025 was 20 December 1968, with 4.8 cm.
Are there tropical nights in Porterville?
Yes: Porterville has on average 44 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Porterville?
In Porterville, between 1940 and 2025, the highest apparent temperature reached 47.0 °C on 4 July 1991, and the lowest was -15.4 °C on 23 December 1990.
Compare Porterville with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Porterville