Rosemead climate — normals and trends
Rosemead (United States) has a hot-summer mediterranean climate (Csa) under the Köppen-Geiger classification. Its mean annual temperature is 17.0 °C and it receives 374 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 August (23.3 °C on average) and the coldest is January (11.4 °C). Rainfall peaks in February.
Rosemead averages 1 frost days, 58 hot days (≥ 30 °C) and 36 rainy days per year.
Rosemead has warmed by +1.8 °C between 1940 and 2025, or +0.21 °C per decade. This trend is statistically significant.
The number of frost days there went from about 2 to 0 per year over the period.
The hottest day of the period reached 44.2 °C (on 5 September 2020) and the coldest -3.2 °C (on 4 January 1949).
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
RosemeadCalifornia
- coords
- 34.08°, -118.07°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
17.0°C
Average daily high
23.3°C
Average daily low
12.1°C
Annual rainfall
374mm
Sunshine / day
11.2h
Mean relative humidity
62%
Average peak wind
12.5km/h
Seasonal range
11.9°C
Frost days (< 0 °C)
1 d/yr
Hot days (≥ 30 °C)
58 d/yr
Rainy days (≥ 1 mm)
36 d/yr
Annual snowfall
0.7 cm
Average feels-like high
22.8 °C
Average feels-like low
11.1 °C
Average peak gust
30.5 km/h
Tropical nights (≥ 20 °C)
12 d/yr
Solar radiation
20.3 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.8 °C
since 1940
+0.2 °C per decade · r² = 0.48 · 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
44.2 °C
5 September 2020
Coldest day
-3.2 °C
4 January 1949
Wettest day
108 mm
1 March 1983
Windiest day
35.7 km/h
1 March 1983
Strongest gust
90.4 km/h
1 March 1983
Hottest feels-like
43.6 °C
6 July 2018
Coldest feels-like
-8.0 °C
4 January 1949
Snowiest day
3.7 cm
4 January 1974
Sunniest day
14.0 h
6 June 1940
Normals computed over complete calendar years 1940–2025.
A specific year
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Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 18.9 °C | +1.5 °C | 18 mm | -60 mm |
| Feb | 19.7 °C | +1.7 °C | 88 mm | +6 mm |
| Mar | 18.4 °C | -0.7 °C | 61 mm | -1 mm |
| Apr | 20.8 °C | -0.6 °C | 14 mm | -13 mm |
| May | 24.1 °C | +0.7 °C | 7 mm | -1 mm |
| Jun | 26.5 °C | +0.1 °C | 3 mm | +1 mm |
| Jul | 27.7 °C | -2.1 °C | 1 mm | -1 mm |
| Aug | 30.6 °C | +0.3 °C | 0 mm | -3 mm |
| Sep | 28.9 °C | -0.2 °C | 10 mm | +4 mm |
| Oct | 25.1 °C | -0.5 °C | 41 mm | +27 mm |
| Nov | 21.4 °C | +0.1 °C | 118 mm | +84 mm |
| Dec | 20.5 °C | +2.6 °C | 107 mm | +51 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 Rosemead?
Rosemead has a hot-summer mediterranean climate (Köppen Csa). Over 1940-2025, the average annual temperature is 17.0 °C and it receives 374 mm of precipitation per year.
What is the hottest day ever recorded in Rosemead?
The hottest day measured in Rosemead between 1940 and 2025 was 5 September 2020, reaching 44.2 °C.
What is the coldest day in Rosemead?
The coldest day measured in Rosemead between 1940 and 2025 was 4 January 1949, at -3.2 °C.
Does it snow in Rosemead?
Almost never: Rosemead sees virtually no snow, with about 1 frost days per year.
Has the climate of Rosemead warmed?
Yes: Rosemead warmed by +1.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Rosemead?
The wettest day measured in Rosemead between 1940 and 2025 was 1 March 1983, with 108 mm of rain in 24 hours.
What was the windiest day in Rosemead?
The windiest day measured in Rosemead between 1940 and 2025 was 1 March 1983, with winds reaching 35.7 km/h.
What is the warmest month in Rosemead?
The warmest month in Rosemead is August (23.3 °C on average); the coldest is January (11.4 °C).
How much does it rain in Rosemead?
Rosemead receives on average 374 mm of precipitation per year, spread over about 36 rainy days.
Is it sunny in Rosemead?
Rosemead 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 Rosemead?
The heaviest 24-hour snowfall measured in Rosemead between 1940 and 2025 was 4 January 1974, with 3.7 cm.
Are there tropical nights in Rosemead?
Yes: Rosemead has on average 12 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Rosemead?
In Rosemead, between 1940 and 2025, the highest apparent temperature reached 43.6 °C on 6 July 2018, and the lowest was -8.0 °C on 4 January 1949.
Compare Rosemead with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Rosemead