Usa River climate — normals and trends
Usa River (Tanzania) has a warm-summer mediterranean climate (Csb) under the Köppen-Geiger classification. Its mean annual temperature is 17.9 °C and it receives 852 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 February (19.8 °C on average) and the coldest is July (15.0 °C). Rainfall peaks in April.
Usa River averages 0 frost days, 1 hot days (≥ 30 °C) and 135 rainy days per year.
Usa River has warmed by +1.4 °C between 1940 and 2025, or +0.16 °C per decade. This trend is statistically significant.
The hottest day of the period reached 32.0 °C (on 27 March 1941) and the coldest 4.7 °C (on 11 July 1944).
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
Usa RiverArusha
- coords
- -3.37°, 36.85°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
17.9°C
Average daily high
23.6°C
Average daily low
13.3°C
Annual rainfall
852mm
Sunshine / day
10.7h
Mean relative humidity
75%
Average peak wind
9.8km/h
Seasonal range
4.8°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
1 d/yr
Rainy days (≥ 1 mm)
135 d/yr
Annual snowfall
0.0 cm
Average feels-like high
24.5 °C
Average feels-like low
13.2 °C
Average peak gust
33.4 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
19.4 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.4 °C
since 1940
+0.2 °C per decade · r² = 0.60 · 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
32.0 °C
27 March 1941
Coldest day
4.7 °C
11 July 1944
Wettest day
94 mm
22 April 1971
Windiest day
19.1 km/h
14 August 1993
Strongest gust
59.8 km/h
19 September 1943
Hottest feels-like
34.7 °C
25 February 2005
Coldest feels-like
1.4 °C
11 July 1944
Sunniest day
12.2 h
21 December 2023
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 | 25.7 °C | +0.3 °C | 110 mm | +16 mm |
| Feb | 27.0 °C | +0.9 °C | 9 mm | -79 mm |
| Mar | 25.5 °C | -0.1 °C | 153 mm | -0 mm |
| Apr | 23.9 °C | +0.4 °C | 140 mm | -31 mm |
| May | 22.4 °C | +0.6 °C | 37 mm | -17 mm |
| Jun | 21.4 °C | +0.5 °C | 18 mm | +7 mm |
| Jul | 20.6 °C | +0.1 °C | 5 mm | -1 mm |
| Aug | 21.8 °C | +0.2 °C | 10 mm | +5 mm |
| Sep | 25.1 °C | +1.5 °C | 2 mm | -5 mm |
| Oct | 24.8 °C | -0.1 °C | 49 mm | +18 mm |
| Nov | 25.5 °C | +1.1 °C | 27 mm | -85 mm |
| Dec | 25.3 °C | +0.9 °C | 146 mm | +25 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 Usa River?
Usa River has a warm-summer mediterranean climate (Köppen Csb). Over 1940-2025, the average annual temperature is 17.9 °C and it receives 852 mm of precipitation per year.
What is the hottest day ever recorded in Usa River?
The hottest day measured in Usa River between 1940 and 2025 was 27 March 1941, reaching 32.0 °C.
What is the coldest day in Usa River?
The coldest day measured in Usa River between 1940 and 2025 was 11 July 1944, at 4.7 °C.
Does it snow in Usa River?
Almost never: Usa River sees virtually no snow, with about 0 frost days per year.
Has the climate of Usa River warmed?
Yes: Usa River warmed by +1.4 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Usa River?
The wettest day measured in Usa River between 1940 and 2025 was 22 April 1971, with 94 mm of rain in 24 hours.
What was the windiest day in Usa River?
The windiest day measured in Usa River between 1940 and 2025 was 14 August 1993, with winds reaching 19.1 km/h.
What is the warmest month in Usa River?
The warmest month in Usa River is February (19.8 °C on average); the coldest is July (15.0 °C).
How much does it rain in Usa River?
Usa River receives on average 852 mm of precipitation per year, spread over about 135 rainy days.
Is it sunny in Usa River?
Usa River gets on average 10.7 hours of sunshine per day, roughly 3,905 hours per year over 1940-2025.
Are there tropical nights in Usa River?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Usa River.
What was the most extreme apparent temperature in Usa River?
In Usa River, between 1940 and 2025, the highest apparent temperature reached 34.7 °C on 25 February 2005, and the lowest was 1.4 °C on 11 July 1944.
Compare Usa River with another city
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Nearby cities
The climate around Usa River