La Unión climate — normals and trends
La Unión (Peru) has a hot desert climate (BWh) under the Köppen-Geiger classification. Its mean annual temperature is 22.6 °C and it receives 164 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 (25.9 °C on average) and the coldest is August (20.0 °C). Rainfall peaks in March.
La Unión averages 0 frost days, 87 hot days (≥ 30 °C) and 26 rainy days per year.
La Unión has warmed by +1.0 °C between 1940 and 2025, or +0.12 °C per decade. This trend is statistically significant.
The hottest day of the period reached 34.8 °C (on 10 February 1987) and the coldest 13.1 °C (on 14 October 1954).
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
La UniónPiura
- coords
- -5.40°, -80.74°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
22.6°C
Average daily high
27.8°C
Average daily low
19.3°C
Annual rainfall
164mm
Sunshine / day
10.8h
Mean relative humidity
73%
Average peak wind
21.4km/h
Seasonal range
5.9°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
87 d/yr
Rainy days (≥ 1 mm)
26 d/yr
Annual snowfall
0.0 cm
Average feels-like high
29.6 °C
Average feels-like low
20.5 °C
Average peak gust
40.0 km/h
Tropical nights (≥ 20 °C)
139 d/yr
Solar radiation
21.9 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.0 °C
since 1940
+0.1 °C per decade · r² = 0.12 · 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
34.8 °C
10 February 1987
Coldest day
13.1 °C
14 October 1954
Wettest day
177 mm
29 January 1998
Windiest day
34.8 km/h
15 April 1962
Strongest gust
63.4 km/h
15 April 1962
Hottest feels-like
40.4 °C
28 February 1983
Coldest feels-like
11.9 °C
11 July 1954
Sunniest day
12.3 h
30 December 2025
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 | 29.8 °C | -0.1 °C | 15 mm | -9 mm |
| Feb | 31.1 °C | +0.3 °C | 55 mm | +26 mm |
| Mar | 32.5 °C | +1.6 °C | 48 mm | -4 mm |
| Apr | 29.9 °C | -0.1 °C | 58 mm | +32 mm |
| May | 28.2 °C | -0.1 °C | 12 mm | +2 mm |
| Jun | 26.1 °C | -0.2 °C | 9 mm | +5 mm |
| Jul | 25.6 °C | +0.6 °C | 0 mm | -3 mm |
| Aug | 25.2 °C | +0.2 °C | 0 mm | -0 mm |
| Sep | 26.0 °C | +0.3 °C | 2 mm | +1 mm |
| Oct | 26.6 °C | +0.3 °C | 6 mm | +3 mm |
| Nov | 27.3 °C | +0.2 °C | 19 mm | +16 mm |
| Dec | 27.8 °C | -0.7 °C | 3 mm | -5 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 La Unión?
La Unión has a hot desert climate (Köppen BWh). Over 1940-2025, the average annual temperature is 22.6 °C and it receives 164 mm of precipitation per year.
What is the hottest day ever recorded in La Unión?
The hottest day measured in La Unión between 1940 and 2025 was 10 February 1987, reaching 34.8 °C.
What is the coldest day in La Unión?
The coldest day measured in La Unión between 1940 and 2025 was 14 October 1954, at 13.1 °C.
Does it snow in La Unión?
Almost never: La Unión sees virtually no snow, with about 0 frost days per year.
Has the climate of La Unión warmed?
Yes: La Unión warmed by +1.0 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in La Unión?
The wettest day measured in La Unión between 1940 and 2025 was 29 January 1998, with 177 mm of rain in 24 hours.
What was the windiest day in La Unión?
The windiest day measured in La Unión between 1940 and 2025 was 15 April 1962, with winds reaching 34.8 km/h.
What is the warmest month in La Unión?
The warmest month in La Unión is February (25.9 °C on average); the coldest is August (20.0 °C).
How much does it rain in La Unión?
La Unión receives on average 164 mm of precipitation per year, spread over about 26 rainy days.
Is it sunny in La Unión?
La Unión gets on average 10.8 hours of sunshine per day, roughly 3,942 hours per year over 1940-2025.
Are there tropical nights in La Unión?
Yes: La Unión has on average 139 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in La Unión?
In La Unión, between 1940 and 2025, the highest apparent temperature reached 40.4 °C on 28 February 1983, and the lowest was 11.9 °C on 11 July 1954.
Compare La Unión with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around La Unión