Alajuela climate — normals and trends

Q: What is the climate of Alajuela?

Alajuela has a tropical monsoon climate (Köppen Am). Over 1940-2025, the average annual temperature is 20.0 °C and it receives 2,756 mm of precipitation per year.

Q: What is the hottest day ever recorded in Alajuela?

The hottest day measured in Alajuela between 1940 and 2025 was 9 April 1941, reaching 31.2 °C.

Q: What is the coldest day in Alajuela?

The coldest day measured in Alajuela between 1940 and 2025 was 5 February 1945, at 10.7 °C.

Q: Does it snow in Alajuela?

Almost never: Alajuela sees virtually no snow, with about 0 frost days per year.

Q: Has the climate of Alajuela warmed?

Yes: Alajuela warmed by +1.2 °C between 1940 and 2025, a statistically significant trend.

Q: What is the wettest day in Alajuela?

The wettest day measured in Alajuela between 1940 and 2025 was 25 October 2017, with 213 mm of rain in 24 hours.

Q: What was the windiest day in Alajuela?

The windiest day measured in Alajuela between 1940 and 2025 was 3 January 1979, with winds reaching 27.1 km/h.

Q: What is the warmest month in Alajuela?

The warmest month in Alajuela is April (21.1 °C on average); the coldest is November (19.4 °C).

Q: How much does it rain in Alajuela?

Alajuela receives on average 2,756 mm of precipitation per year, spread over about 233 rainy days.

Q: Is it sunny in Alajuela?

Alajuela gets on average 8.7 hours of sunshine per day, roughly 3,175 hours per year over 1940-2025.

Alajuela (Costa Rica) has a tropical monsoon climate (Am) under the Köppen-Geiger classification. Its mean annual temperature is 20.0 °C and it receives 2,756 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 (21.1 °C on average) and the coldest is November (19.4 °C). Rainfall peaks in October.

Alajuela averages 0 frost days, 1 hot days (≥ 30 °C) and 233 rainy days per year.

Alajuela 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 31.2 °C (on 9 April 1941) and the coldest 10.7 °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

AlajuelaAlajuela Province

coords: 10.02°, -84.21°
period: 1940–2025 · 86 yrs

AmTropical monsoonWarmest monthAprilColdest monthNovemberWettest monthOctoberDriest monthFebruary

Mean daily temperature

20.0°C

Average daily high

24.6°C

Average daily low

16.9°C

Annual rainfall

2,756mm

Sunshine / day

8.7h

Mean relative humidity

82%

Average peak wind

8.9km/h

Seasonal range

1.7°C

Frost days (< 0 °C)

0 d/yr

Hot days (≥ 30 °C)

1 d/yr

Rainy days (≥ 1 mm)

233 d/yr

Annual snowfall

0.0 cm

Average feels-like high

27.4 °C

Average feels-like low

17.6 °C

Average peak gust

32.0 km/h

Tropical nights (≥ 20 °C)

1 d/yr

Solar radiation

16.5 MJ/m²

Has the climate changed?

One stripe per year, 1940 to 2025

+1.2 °C

since 1940

+0.1 °C per decade · r² = 0.57 · p = < 0.001

19402025

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

31.2 °C

9 April 1941

Coldest day

10.7 °C

5 February 1945

Wettest day

213 mm

25 October 2017

Windiest day

27.1 km/h

3 January 1979

Strongest gust

83.9 km/h

3 January 1979

Hottest feels-like

35.2 °C

21 March 1987

Coldest feels-like

7.8 °C

27 February 1944

Sunniest day

12.6 h

17 June 1988

Year	Hottest day	Coldest day	Annual mean	Rainfall	Hot days
2025	28.6 °C8 April 2025	14.4 °C20 March 2025	20.6 °C	2,363 mm	0
2024	29.6 °C18 April 2024	14.6 °C3 March 2024	20.9 °C	3,313 mm	0
2023	28.2 °C18 May 2023	14.4 °C6 January 2023	20.8 °C	2,584 mm	0
2022	27.5 °C31 March 2022	13.0 °C3 February 2022	20.1 °C	3,329 mm	0
2021	27.2 °C14 February 2021	13.7 °C4 March 2021	20.2 °C	2,658 mm	0
2020	29.2 °C5 April 2020	14.9 °C7 February 2020	20.6 °C	2,812 mm	0
2019	28.5 °C28 April 2019	14.3 °C8 January 2019	20.7 °C	2,491 mm	0
2018	27.9 °C11 March 2018	13.7 °C1 March 2018	20.3 °C	2,163 mm	0
2017	28.4 °C1 April 2017	13.7 °C19 February 2017	20.4 °C	3,074 mm	0
2016	29.4 °C3 April 2016	14.8 °C1 February 2016	20.8 °C	2,729 mm	0
2015	28.4 °C28 April 2015	13.7 °C27 March 2015	20.9 °C	1,735 mm	0
2014	28.7 °C7 April 2014	13.7 °C20 February 2014	20.6 °C	2,401 mm	0
2013	28.0 °C21 March 2013	14.4 °C27 December 2013	20.5 °C	2,523 mm	0
2012	27.6 °C4 April 2012	13.9 °C18 February 2012	20.3 °C	2,341 mm	0
2011	28.4 °C1 April 2011	13.3 °C5 March 2011	20.1 °C	3,067 mm	0
2010	28.4 °C5 February 2010	14.0 °C14 December 2010	20.3 °C	4,325 mm	0
2009	29.0 °C7 September 2009	13.6 °C2 February 2009	20.4 °C	2,421 mm	0
2008	28.1 °C14 May 2008	12.6 °C3 February 2008	20.0 °C	3,378 mm	0
2007	27.9 °C19 April 2007	14.1 °C9 February 2007	20.3 °C	2,938 mm	0
2006	27.9 °C2 May 2006	13.4 °C22 November 2006	20.3 °C	2,421 mm	0
2005	28.8 °C30 April 2005	14.0 °C15 December 2005	20.3 °C	2,572 mm	0
2004	30.1 °C12 April 2004	12.2 °C21 January 2004	20.4 °C	2,741 mm	1
2003	29.2 °C5 March 2003	13.7 °C28 March 2003	20.3 °C	3,190 mm	0
2002	28.7 °C3 May 2002	12.9 °C14 January 2002	20.5 °C	2,596 mm	0
2001	28.7 °C4 May 2001	13.2 °C18 January 2001	19.9 °C	2,229 mm	0
2000	28.3 °C30 March 2000	12.8 °C11 January 2000	19.6 °C	2,427 mm	0
1999	27.8 °C1 April 1999	12.9 °C28 February 1999	19.2 °C	3,009 mm	0
1998	29.6 °C5 April 1998	13.5 °C11 January 1998	20.3 °C	2,408 mm	0
1997	28.8 °C13 April 1997	13.6 °C5 January 1997	20.1 °C	1,703 mm	0
1996	28.6 °C8 April 1996	12.6 °C27 January 1996	19.7 °C	3,343 mm	0
1995	28.5 °C9 April 1995	13.3 °C14 January 1995	20.0 °C	3,775 mm	0
1994	29.2 °C10 April 1994	12.8 °C30 January 1994	20.3 °C	1,716 mm	0
1993	28.2 °C13 March 1993	13.0 °C2 March 1993	20.0 °C	2,614 mm	0
1992	30.6 °C4 April 1992	13.8 °C12 January 1992	20.3 °C	2,101 mm	4
1991	31.2 °C22 April 1991	13.4 °C9 February 1991	20.3 °C	1,807 mm	3
1990	30.4 °C4 April 1990	13.9 °C19 February 1990	20.4 °C	2,225 mm	2
1989	29.1 °C8 May 1989	13.6 °C14 March 1989	20.0 °C	2,231 mm	0
1988	30.1 °C1 April 1988	13.4 °C20 January 1988	20.2 °C	2,778 mm	1
1987	31.2 °C28 March 1987	13.5 °C8 January 1987	20.8 °C	2,306 mm	10
1986	30.3 °C9 May 1986	12.8 °C8 January 1986	19.9 °C	2,166 mm	4
1985	29.9 °C22 March 1985	13.1 °C5 April 1985	19.7 °C	2,592 mm	0
1984	30.0 °C30 March 1984	13.0 °C24 January 1984	19.8 °C	2,211 mm	1
1983	31.2 °C15 April 1983	13.7 °C24 December 1983	20.6 °C	2,464 mm	11
1982	30.2 °C6 April 1982	13.6 °C31 January 1982	20.4 °C	2,086 mm	3
1981	28.8 °C2 March 1981	12.7 °C23 January 1981	19.9 °C	3,095 mm	0
1980	30.4 °C4 May 1980	13.6 °C15 February 1980	20.2 °C	2,572 mm	2
1979	28.4 °C19 March 1979	13.1 °C20 January 1979	19.9 °C	3,396 mm	0
1978	29.0 °C23 April 1978	13.0 °C20 December 1978	20.0 °C	2,771 mm	0
1977	29.7 °C28 March 1977	13.1 °C10 January 1977	20.2 °C	2,225 mm	0
1976	28.5 °C6 April 1976	10.9 °C28 December 1976	19.7 °C	2,272 mm	0
1975	30.5 °C17 April 1975	12.6 °C30 December 1975	19.5 °C	3,809 mm	1
1974	28.1 °C20 April 1974	12.3 °C19 December 1974	19.4 °C	3,038 mm	0
1973	28.8 °C20 March 1973	13.3 °C30 December 1973	19.8 °C	3,214 mm	0
1972	27.5 °C1 April 1972	13.5 °C7 January 1972	19.9 °C	2,565 mm	0
1971	27.4 °C1 April 1971	13.2 °C2 February 1971	19.3 °C	3,083 mm	0
1970	27.0 °C9 March 1970	13.1 °C24 January 1970	19.6 °C	3,615 mm	0
1969	29.2 °C7 May 1969	13.7 °C9 January 1969	20.2 °C	3,644 mm	0
1968	27.3 °C27 April 1968	12.6 °C10 March 1968	19.6 °C	3,164 mm	0
1967	27.8 °C6 March 1967	13.1 °C20 March 1967	19.7 °C	2,448 mm	0
1966	28.0 °C28 March 1966	13.8 °C29 December 1966	19.9 °C	2,769 mm	0
1965	29.4 °C3 May 1965	12.3 °C15 April 1965	19.7 °C	2,577 mm	0
1964	29.9 °C25 March 1964	12.9 °C25 December 1964	19.7 °C	2,606 mm	0
1963	27.8 °C18 March 1963	12.9 °C14 January 1963	19.6 °C	2,595 mm	0
1962	27.7 °C6 April 1962	13.2 °C10 January 1962	19.4 °C	2,742 mm	0
1961	29.3 °C13 April 1961	13.5 °C10 February 1961	20.0 °C	1,971 mm	0
1960	27.5 °C16 March 1960	13.6 °C13 February 1960	19.7 °C	2,420 mm	0
1959	27.7 °C12 March 1959	12.6 °C16 January 1959	19.8 °C	1,888 mm	0
1958	28.2 °C19 March 1958	14.1 °C5 November 1958	20.0 °C	3,053 mm	0
1957	29.8 °C2 May 1957	14.0 °C23 January 1957	20.0 °C	2,343 mm	0
1956	29.8 °C28 April 1956	12.9 °C12 January 1956	19.2 °C	3,272 mm	0
1955	29.1 °C7 May 1955	12.2 °C9 December 1955	19.7 °C	3,828 mm	0
1954	30.1 °C22 March 1954	13.3 °C30 January 1954	19.6 °C	3,186 mm	2
1953	29.0 °C14 April 1953	13.0 °C19 January 1953	20.0 °C	2,812 mm	0
1952	30.2 °C4 April 1952	13.5 °C8 March 1952	19.9 °C	2,845 mm	4
1951	27.5 °C19 April 1951	13.7 °C9 February 1951	19.8 °C	2,842 mm	0
1950	29.7 °C26 April 1950	13.4 °C28 February 1950	19.6 °C	3,059 mm	0
1949	30.6 °C28 April 1949	13.3 °C18 January 1949	20.0 °C	3,544 mm	6
1948	28.1 °C25 April 1948	12.7 °C24 February 1948	19.3 °C	4,172 mm	0
1947	28.5 °C10 April 1947	12.1 °C30 December 1947	19.3 °C	3,023 mm	0
1946	29.1 °C26 April 1946	11.8 °C5 January 1946	19.2 °C	2,579 mm	0
1945	27.3 °C26 April 1945	10.7 °C5 February 1945	19.0 °C	3,239 mm	0
1944	28.0 °C17 April 1944	11.5 °C27 February 1944	19.1 °C	3,696 mm	0
1943	26.7 °C14 April 1943	12.4 °C20 December 1943	18.8 °C	3,114 mm	0
1942	28.4 °C16 March 1942	12.6 °C3 January 1942	19.0 °C	3,677 mm	0
1941	31.2 °C9 April 1941	13.3 °C5 January 1941	19.7 °C	2,041 mm	7
1940	28.7 °C13 May 1940	12.4 °C12 January 1940	19.6 °C	1,860 mm	0

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?

Year

Across the whole year

Average daily high

25.2 °C

+0.6 °C

Hot days (≥ 30 °C)

0 d/yr

-1

Frost days (< 0 °C)

0 d/yr

Annual rainfall

2363 mm

-393 mm

Month by month

	High	vs. normal	Precipitation	vs. normal
Jan	24.5 °C	+0.1 °C	47 mm	+16 mm
Feb	25.5 °C	+0.2 °C	22 mm	-1 mm
Mar	27.0 °C	+0.6 °C	15 mm	-13 mm
Apr	26.1 °C	-0.6 °C	43 mm	-21 mm
May	25.6 °C	+0.4 °C	162 mm	-142 mm
Jun	24.5 °C	+0.3 °C	423 mm	+25 mm
Jul	25.3 °C	+1.2 °C	171 mm	-140 mm
Aug	25.3 °C	+1.1 °C	255 mm	-90 mm
Sep	24.9 °C	+0.8 °C	493 mm	+53 mm
Oct	24.2 °C	+0.7 °C	472 mm	-2 mm
Nov	24.8 °C	+1.4 °C	172 mm	-79 mm
Dec	25.0 °C	+1.3 °C	87 mm	+2 mm

The year's extremes

Hottest day

28.6 °C

8 Apr 2025

Coldest day

14.4 °C

20 Mar 2025

Wettest day

103.6 mm

28 Sep 2025

Windiest day

19.1 km/h

25 Jan 2025

Strongest gust

56.9 km/h

25 Jan 2025

Hottest feels-like

32.3 °C

8 Apr 2025

Coldest feels-like

13.0 °C

19 Dec 2025

Sunniest day

12.3 h

16 Jul 2025

What was the weather like that day?

Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.

Date

Frequently asked questions

What is the climate of Alajuela?

Alajuela has a tropical monsoon climate (Köppen Am). Over 1940-2025, the average annual temperature is 20.0 °C and it receives 2,756 mm of precipitation per year.

What is the hottest day ever recorded in Alajuela?

The hottest day measured in Alajuela between 1940 and 2025 was 9 April 1941, reaching 31.2 °C.

What is the coldest day in Alajuela?

The coldest day measured in Alajuela between 1940 and 2025 was 5 February 1945, at 10.7 °C.

Does it snow in Alajuela?

Almost never: Alajuela sees virtually no snow, with about 0 frost days per year.

Has the climate of Alajuela warmed?

Yes: Alajuela warmed by +1.2 °C between 1940 and 2025, a statistically significant trend.

What is the wettest day in Alajuela?

The wettest day measured in Alajuela between 1940 and 2025 was 25 October 2017, with 213 mm of rain in 24 hours.

What was the windiest day in Alajuela?

The windiest day measured in Alajuela between 1940 and 2025 was 3 January 1979, with winds reaching 27.1 km/h.

What is the warmest month in Alajuela?

The warmest month in Alajuela is April (21.1 °C on average); the coldest is November (19.4 °C).

How much does it rain in Alajuela?

Alajuela receives on average 2,756 mm of precipitation per year, spread over about 233 rainy days.

Is it sunny in Alajuela?

Alajuela gets on average 8.7 hours of sunshine per day, roughly 3,175 hours per year over 1940-2025.

Are there tropical nights in Alajuela?

Yes: Alajuela has on average 1 tropical nights per year (temperature staying above 20 °C), over 1940-2025.

What was the most extreme apparent temperature in Alajuela?

In Alajuela, between 1940 and 2025, the highest apparent temperature reached 35.2 °C on 21 March 1987, and the lowest was 7.8 °C on 27 February 1944.

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