Aserrí climate — normals and trends
Aserrí (Costa Rica) has a subtropical highland, dry winter climate (Cwb) under the Köppen-Geiger classification. Its mean annual temperature is 17.6 °C and it receives 3,416 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 April (18.3 °C on average) and the coldest is January (16.9 °C). Rainfall peaks in October.
Aserrí averages 0 frost days, 0 hot days (≥ 30 °C) and 269 rainy days per year.
Aserrí has warmed by +1.2 °C between 1940 and 2025, or +0.14 °C per decade. This trend is statistically significant.
The hottest day of the period reached 28.3 °C (on 9 April 1941) and the coldest 8.5 °C (on 5 February 1945).
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
AserríSan José
- coords
- 9.86°, -84.09°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
17.6°C
Average daily high
21.9°C
Average daily low
14.5°C
Annual rainfall
3,416mm
Sunshine / day
9.0h
Mean relative humidity
85%
Average peak wind
7.2km/h
Seasonal range
1.4°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
269 d/yr
Annual snowfall
0.0 cm
Average feels-like high
24.4 °C
Average feels-like low
14.6 °C
Average peak gust
29.5 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
16.7 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.2 °C
since 1940
+0.1 °C per decade · r² = 0.53 · 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
28.3 °C
9 April 1941
Coldest day
8.5 °C
5 February 1945
Wettest day
180 mm
11 November 1975
Windiest day
19.0 km/h
27 January 1988
Strongest gust
68.0 km/h
27 January 1988
Hottest feels-like
32.0 °C
3 June 1982
Coldest feels-like
5.9 °C
27 February 1944
Sunniest day
12.6 h
7 June 1988
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 | 21.8 °C | +0.1 °C | 61 mm | +26 mm |
| Feb | 22.1 °C | -0.3 °C | 49 mm | +17 mm |
| Mar | 23.1 °C | -0.1 °C | 44 mm | -12 mm |
| Apr | 22.5 °C | -0.7 °C | 115 mm | -15 mm |
| May | 22.7 °C | +0.4 °C | 319 mm | -103 mm |
| Jun | 22.0 °C | +0.2 °C | 497 mm | +27 mm |
| Jul | 22.8 °C | +1.2 °C | 244 mm | -135 mm |
| Aug | 22.6 °C | +1.0 °C | 290 mm | -125 mm |
| Sep | 22.6 °C | +1.0 °C | 482 mm | -29 mm |
| Oct | 21.7 °C | +0.5 °C | 596 mm | +39 mm |
| Nov | 22.2 °C | +1.2 °C | 208 mm | -100 mm |
| Dec | 21.8 °C | +0.6 °C | 134 mm | +32 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 Aserrí?
Aserrí has a subtropical highland, dry winter climate (Köppen Cwb). Over 1940-2025, the average annual temperature is 17.6 °C and it receives 3,416 mm of precipitation per year.
What is the hottest day ever recorded in Aserrí?
The hottest day measured in Aserrí between 1940 and 2025 was 9 April 1941, reaching 28.3 °C.
What is the coldest day in Aserrí?
The coldest day measured in Aserrí between 1940 and 2025 was 5 February 1945, at 8.5 °C.
Does it snow in Aserrí?
Almost never: Aserrí sees virtually no snow, with about 0 frost days per year.
Has the climate of Aserrí warmed?
Yes: Aserrí warmed by +1.2 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Aserrí?
The wettest day measured in Aserrí between 1940 and 2025 was 11 November 1975, with 180 mm of rain in 24 hours.
What was the windiest day in Aserrí?
The windiest day measured in Aserrí between 1940 and 2025 was 27 January 1988, with winds reaching 19.0 km/h.
What is the warmest month in Aserrí?
The warmest month in Aserrí is April (18.3 °C on average); the coldest is January (16.9 °C).
How much does it rain in Aserrí?
Aserrí receives on average 3,416 mm of precipitation per year, spread over about 269 rainy days.
Is it sunny in Aserrí?
Aserrí gets on average 9.0 hours of sunshine per day, roughly 3,285 hours per year over 1940-2025.
Are there tropical nights in Aserrí?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Aserrí.
What was the most extreme apparent temperature in Aserrí?
In Aserrí, between 1940 and 2025, the highest apparent temperature reached 32.0 °C on 3 June 1982, and the lowest was 5.9 °C on 27 February 1944.
Compare Aserrí with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Aserrí