La Unión climate — normals and trends
La Unión (Colombia) has a tropical rainforest climate (Af) under the Köppen-Geiger classification. Its mean annual temperature is 20.7 °C and it receives 6,629 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 (20.9 °C on average) and the coldest is October (20.4 °C). Rainfall peaks in May.
La Unión averages 0 frost days, 0 hot days (≥ 30 °C) and 358 rainy days per year.
La Unión has warmed by +2.6 °C between 1940 and 2025, or +0.31 °C per decade. This trend is statistically significant.
The hottest day of the period reached 31.6 °C (on 19 July 2023) and the coldest 11.7 °C (on 22 November 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 UniónValle del Cauca Department
- coords
- 4.53°, -76.10°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
20.7°C
Average daily high
24.9°C
Average daily low
17.6°C
Annual rainfall
6,629mm
Sunshine / day
7.3h
Mean relative humidity
89%
Average peak wind
5.2km/h
Seasonal range
0.5°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
358 d/yr
Annual snowfall
0.0 cm
Average feels-like high
28.7 °C
Average feels-like low
19.8 °C
Average peak gust
20.3 km/h
Tropical nights (≥ 20 °C)
4 d/yr
Solar radiation
14.2 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+2.6 °C
since 1940
+0.3 °C per decade · r² = 0.75 · 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
31.6 °C
19 July 2023
Coldest day
11.7 °C
22 November 1954
Wettest day
172 mm
1 March 1978
Windiest day
14.9 km/h
16 April 1990
Strongest gust
36.4 km/h
24 March 1980
Hottest feels-like
36.6 °C
23 March 2010
Coldest feels-like
11.3 °C
22 November 1954
Sunniest day
12.0 h
9 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 | 26.4 °C | +1.4 °C | 376 mm | -21 mm |
| Feb | 24.8 °C | -0.3 °C | 728 mm | +302 mm |
| Mar | 25.0 °C | -0.2 °C | 637 mm | +98 mm |
| Apr | 25.6 °C | +0.8 °C | 793 mm | +99 mm |
| May | 25.2 °C | +0.3 °C | 731 mm | -16 mm |
| Jun | 25.4 °C | +0.6 °C | 769 mm | +161 mm |
| Jul | 26.7 °C | +1.6 °C | 303 mm | -186 mm |
| Aug | 26.2 °C | +1.1 °C | 406 mm | -92 mm |
| Sep | 25.7 °C | +0.7 °C | 517 mm | -41 mm |
| Oct | 24.3 °C | -0.3 °C | 615 mm | -34 mm |
| Nov | 24.4 °C | -0.1 °C | 645 mm | +76 mm |
| Dec | 24.7 °C | 0.0 °C | 408 mm | -47 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 tropical rainforest climate (Köppen Af). Over 1940-2025, the average annual temperature is 20.7 °C and it receives 6,629 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 19 July 2023, reaching 31.6 °C.
What is the coldest day in La Unión?
The coldest day measured in La Unión between 1940 and 2025 was 22 November 1954, at 11.7 °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 +2.6 °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 1 March 1978, with 172 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 16 April 1990, with winds reaching 14.9 km/h.
What is the warmest month in La Unión?
The warmest month in La Unión is July (20.9 °C on average); the coldest is October (20.4 °C).
How much does it rain in La Unión?
La Unión receives on average 6,629 mm of precipitation per year, spread over about 358 rainy days.
Is it sunny in La Unión?
La Unión gets on average 7.3 hours of sunshine per day, roughly 2,665 hours per year over 1940-2025.
Are there tropical nights in La Unión?
Yes: La Unión has on average 4 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 36.6 °C on 23 March 2010, and the lowest was 11.3 °C on 22 November 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