San Juan climate — normals and trends

Q: What is the climate of San Juan?

San Juan has a tropical savanna climate (Köppen Aw). Over 1940-2025, the average annual temperature is 21.7 °C and it receives 911 mm of precipitation per year.

Q: What is the hottest day ever recorded in San Juan?

The hottest day measured in San Juan between 1940 and 2025 was 12 July 2023, reaching 34.1 °C.

Q: What is the coldest day in San Juan?

The coldest day measured in San Juan between 1940 and 2025 was 13 January 1941, at 10.1 °C.

Q: Does it snow in San Juan?

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

Q: Has the climate of San Juan warmed?

Yes: San Juan warmed by +0.8 °C between 1940 and 2025, a statistically significant trend.

Q: What is the wettest day in San Juan?

The wettest day measured in San Juan between 1940 and 2025 was 22 May 1948, with 223 mm of rain in 24 hours.

Q: What was the windiest day in San Juan?

The windiest day measured in San Juan between 1940 and 2025 was 23 September 1998, with winds reaching 41.4 km/h.

Q: What is the warmest month in San Juan?

The warmest month in San Juan is August (23.2 °C on average); the coldest is January (20.1 °C).

Q: How much does it rain in San Juan?

San Juan receives on average 911 mm of precipitation per year, spread over about 175 rainy days.

Q: Is it sunny in San Juan?

San Juan gets on average 11.1 hours of sunshine per day, roughly 4,052 hours per year over 1940-2025.

San Juan (Dominican Republic) has a tropical savanna climate (Aw) under the Köppen-Geiger classification. Its mean annual temperature is 21.7 °C and it receives 911 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 August (23.2 °C on average) and the coldest is January (20.1 °C). Rainfall peaks in May.

San Juan averages 0 frost days, 7 hot days (≥ 30 °C) and 175 rainy days per year.

San Juan has warmed by +0.8 °C between 1940 and 2025, or +0.09 °C per decade. This trend is statistically significant.

The hottest day of the period reached 34.1 °C (on 12 July 2023) and the coldest 10.1 °C (on 13 January 1941).

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

San JuanSan Juan Province

coords: 18.81°, -71.23°
period: 1940–2025 · 86 yrs

AwTropical savannaWarmest monthAugustColdest monthJanuaryWettest monthMayDriest monthJanuary

Mean daily temperature

21.7°C

Average daily high

26.5°C

Average daily low

17.7°C

Annual rainfall

911mm

Sunshine / day

11.1h

Mean relative humidity

78%

Average peak wind

9.2km/h

Seasonal range

3.1°C

Frost days (< 0 °C)

0 d/yr

Hot days (≥ 30 °C)

7 d/yr

Rainy days (≥ 1 mm)

175 d/yr

Annual snowfall

0.0 cm

Average feels-like high

29.2 °C

Average feels-like low

19.5 °C

Average peak gust

31.7 km/h

Tropical nights (≥ 20 °C)

21 d/yr

Solar radiation

20.0 MJ/m²

Has the climate changed?

One stripe per year, 1940 to 2025

+0.8 °C

since 1940

+0.1 °C per decade · r² = 0.30 · 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

34.1 °C

12 July 2023

Coldest day

10.1 °C

13 January 1941

Wettest day

223 mm

22 May 1948

Windiest day

41.4 km/h

23 September 1998

Strongest gust

143.6 km/h

23 September 1998

Hottest feels-like

38.0 °C

12 July 2023

Coldest feels-like

7.7 °C

2 March 1941

Sunniest day

12.8 h

13 June 2025

Year	Hottest day	Coldest day	Annual mean	Rainfall	Hot days
2025	31.9 °C16 August 2025	13.2 °C26 December 2025	22.6 °C	1,005 mm	11
2024	31.8 °C21 August 2024	12.8 °C23 February 2024	23.0 °C	948 mm	8
2023	34.1 °C12 July 2023	11.8 °C17 January 2023	22.6 °C	939 mm	25
2022	30.7 °C1 August 2022	11.6 °C3 January 2022	22.1 °C	700 mm	8
2021	30.2 °C25 May 2021	12.1 °C2 January 2021	22.0 °C	787 mm	5
2020	32.9 °C29 July 2020	13.3 °C17 January 2020	22.4 °C	918 mm	6
2019	30.2 °C27 July 2019	13.4 °C10 January 2019	22.2 °C	817 mm	5
2018	31.3 °C14 September 2018	12.8 °C5 March 2018	22.1 °C	563 mm	3
2017	31.6 °C19 August 2017	11.7 °C20 January 2017	22.1 °C	1,094 mm	7
2016	31.8 °C29 September 2016	12.5 °C10 March 2016	22.3 °C	1,037 mm	7
2015	32.1 °C27 August 2015	13.0 °C5 January 2015	22.3 °C	577 mm	12
2014	30.3 °C21 August 2014	13.0 °C10 January 2014	22.0 °C	685 mm	4
2013	30.6 °C4 October 2013	12.6 °C11 January 2013	22.0 °C	761 mm	2
2012	30.7 °C30 July 2012	11.4 °C25 January 2012	21.8 °C	1,086 mm	6
2011	31.0 °C2 August 2011	12.4 °C1 January 2011	21.9 °C	965 mm	2
2010	30.5 °C30 August 2010	11.9 °C9 March 2010	22.3 °C	1,029 mm	4
2009	31.6 °C4 September 2009	11.5 °C8 March 2009	21.9 °C	725 mm	5
2008	30.5 °C15 August 2008	10.4 °C31 January 2008	21.5 °C	997 mm	2
2007	30.4 °C16 July 2007	12.6 °C5 January 2007	22.0 °C	982 mm	3
2006	31.2 °C15 August 2006	12.6 °C26 February 2006	22.0 °C	811 mm	1
2005	30.3 °C3 September 2005	11.9 °C4 February 2005	22.1 °C	1,089 mm	2
2004	29.8 °C31 August 2004	12.2 °C27 January 2004	21.6 °C	923 mm	0
2003	30.7 °C11 August 2003	12.0 °C30 December 2003	21.7 °C	911 mm	2
2002	30.1 °C24 September 2002	13.0 °C21 February 2002	21.8 °C	662 mm	1
2001	31.6 °C17 August 2001	12.3 °C28 February 2001	21.8 °C	743 mm	2
2000	31.5 °C7 August 2000	10.5 °C17 January 2000	21.6 °C	632 mm	2
1999	30.8 °C19 July 1999	11.3 °C31 January 1999	21.6 °C	916 mm	5
1998	31.8 °C27 July 1998	12.0 °C9 February 1998	22.3 °C	1,008 mm	28
1997	32.3 °C7 September 1997	13.4 °C3 January 1997	22.2 °C	661 mm	21
1996	31.7 °C8 July 1996	12.6 °C6 December 1996	21.4 °C	980 mm	8
1995	31.3 °C12 August 1995	12.8 °C13 January 1995	21.7 °C	799 mm	3
1994	29.8 °C20 July 1994	13.3 °C1 February 1994	21.4 °C	738 mm	0
1993	29.7 °C10 July 1993	12.5 °C2 March 1993	21.4 °C	1,037 mm	0
1992	29.6 °C21 March 1992	13.4 °C16 December 1992	21.5 °C	1,036 mm	0
1991	31.7 °C8 August 1991	10.9 °C22 December 1991	21.6 °C	760 mm	7
1990	31.4 °C4 October 1990	13.2 °C24 February 1990	21.8 °C	1,018 mm	18
1989	30.9 °C5 September 1989	12.9 °C1 January 1989	21.4 °C	817 mm	4
1988	29.8 °C1 August 1988	12.7 °C18 January 1988	21.5 °C	1,073 mm	0
1987	30.2 °C8 August 1987	12.8 °C25 December 1987	21.9 °C	1,149 mm	1
1986	29.0 °C18 September 1986	12.3 °C2 January 1986	21.3 °C	980 mm	0
1985	31.1 °C7 July 1985	12.8 °C15 December 1985	21.2 °C	914 mm	1
1984	29.6 °C25 August 1984	13.0 °C19 December 1984	21.3 °C	933 mm	0
1983	29.5 °C20 August 1983	13.5 °C8 February 1983	21.7 °C	882 mm	0
1982	30.2 °C20 August 1982	11.4 °C25 February 1982	21.2 °C	716 mm	1
1981	28.7 °C2 October 1981	13.6 °C22 January 1981	21.5 °C	982 mm	0
1980	30.4 °C4 August 1980	12.8 °C10 December 1980	21.7 °C	870 mm	1
1979	28.9 °C30 August 1979	11.3 °C31 March 1979	21.1 °C	1,329 mm	0
1978	30.6 °C31 July 1978	12.6 °C12 February 1978	21.4 °C	1,311 mm	3
1977	28.7 °C17 August 1977	14.2 °C24 February 1977	21.5 °C	1,135 mm	0
1976	28.6 °C3 September 1976	11.8 °C15 January 1976	20.8 °C	1,003 mm	0
1975	29.2 °C15 September 1975	11.8 °C13 January 1975	21.0 °C	1,034 mm	0
1974	28.9 °C17 August 1974	12.8 °C10 January 1974	21.0 °C	1,327 mm	0
1973	29.2 °C1 October 1973	13.3 °C28 December 1973	21.5 °C	1,163 mm	0
1972	30.3 °C1 August 1972	12.0 °C13 March 1972	21.3 °C	1,091 mm	1
1971	28.9 °C19 August 1971	12.6 °C29 December 1971	21.0 °C	992 mm	0
1970	31.8 °C21 August 1970	13.3 °C4 March 1970	21.6 °C	936 mm	3
1969	30.4 °C7 August 1969	13.2 °C19 January 1969	21.8 °C	1,063 mm	1
1968	30.0 °C26 August 1968	12.4 °C7 January 1968	21.2 °C	816 mm	1
1967	30.3 °C20 July 1967	12.5 °C7 January 1967	21.5 °C	565 mm	3
1966	33.2 °C26 August 1966	12.0 °C12 February 1966	21.5 °C	852 mm	15
1965	31.1 °C11 April 1965	11.7 °C9 January 1965	21.5 °C	774 mm	4
1964	32.2 °C23 August 1964	12.3 °C26 January 1964	21.5 °C	802 mm	18
1963	30.2 °C6 July 1963	12.9 °C24 January 1963	21.3 °C	1,147 mm	2
1962	31.3 °C9 August 1962	12.3 °C8 March 1962	21.5 °C	826 mm	11
1961	31.4 °C11 August 1961	12.1 °C19 December 1961	21.4 °C	886 mm	16
1960	31.1 °C5 September 1960	11.5 °C26 December 1960	21.5 °C	1,036 mm	13
1959	31.5 °C27 August 1959	14.1 °C9 February 1959	21.8 °C	767 mm	22
1958	32.9 °C16 August 1958	11.0 °C5 February 1958	22.5 °C	845 mm	47
1957	32.2 °C10 September 1957	11.9 °C11 February 1957	22.0 °C	671 mm	32
1956	31.9 °C21 July 1956	10.1 °C11 January 1956	21.6 °C	671 mm	19
1955	30.5 °C2 September 1955	11.5 °C7 February 1955	21.4 °C	812 mm	3
1954	30.6 °C18 August 1954	12.7 °C18 December 1954	21.0 °C	1,030 mm	2
1953	30.8 °C3 September 1953	12.3 °C19 January 1953	21.5 °C	799 mm	3
1952	31.2 °C24 July 1952	12.0 °C14 January 1952	21.7 °C	754 mm	3
1951	31.4 °C8 September 1951	11.3 °C19 January 1951	21.9 °C	801 mm	23
1950	31.6 °C12 August 1950	12.5 °C14 January 1950	21.4 °C	883 mm	10
1949	32.2 °C23 August 1949	12.4 °C12 January 1949	21.7 °C	749 mm	16
1948	30.0 °C22 August 1948	13.5 °C13 February 1948	21.4 °C	1,163 mm	1
1947	32.4 °C18 September 1947	13.8 °C9 January 1947	22.0 °C	766 mm	22
1946	31.9 °C24 July 1946	12.7 °C8 January 1946	21.6 °C	711 mm	20
1945	29.7 °C3 August 1945	12.7 °C5 January 1945	21.2 °C	1,111 mm	0
1944	32.0 °C9 August 1944	10.5 °C6 December 1944	21.7 °C	888 mm	9
1943	31.1 °C21 August 1943	12.2 °C31 January 1943	21.3 °C	1,025 mm	12
1942	31.8 °C3 August 1942	11.5 °C16 January 1942	21.5 °C	1,127 mm	18
1941	31.8 °C12 August 1941	10.1 °C13 January 1941	21.8 °C	851 mm	17
1940	32.4 °C12 September 1940	13.0 °C9 January 1940	21.4 °C	1,183 mm	12

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

27.4 °C

+0.9 °C

Hot days (≥ 30 °C)

11 d/yr

Frost days (< 0 °C)

0 d/yr

Annual rainfall

1005 mm

+94 mm

Month by month

	High	vs. normal	Precipitation	vs. normal
Jan	27.0 °C	+1.5 °C	13 mm	-5 mm
Feb	26.7 °C	+1.1 °C	16 mm	-17 mm
Mar	26.8 °C	+0.9 °C	70 mm	+3 mm
Apr	27.2 °C	+1.2 °C	84 mm	-24 mm
May	27.3 °C	+1.3 °C	133 mm	-5 mm
Jun	27.8 °C	+1.1 °C	45 mm	-35 mm
Jul	28.3 °C	+0.5 °C	52 mm	-12 mm
Aug	29.3 °C	+1.3 °C	68 mm	-25 mm
Sep	28.2 °C	+0.6 °C	230 mm	+117 mm
Oct	26.6 °C	-0.2 °C	261 mm	+142 mm
Nov	27.0 °C	+0.7 °C	25 mm	-31 mm
Dec	26.5 °C	+0.8 °C	8 mm	-16 mm

The year's extremes

Hottest day

31.9 °C

16 Aug 2025

Coldest day

13.2 °C

26 Dec 2025

Wettest day

62.8 mm

25 Sep 2025

Windiest day

16.0 km/h

29 Oct 2025

Strongest gust

55.4 km/h

29 Oct 2025

Hottest feels-like

37.4 °C

16 Aug 2025

Coldest feels-like

13.0 °C

26 Dec 2025

Sunniest day

12.8 h

13 Jun 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 San Juan?

San Juan has a tropical savanna climate (Köppen Aw). Over 1940-2025, the average annual temperature is 21.7 °C and it receives 911 mm of precipitation per year.

What is the hottest day ever recorded in San Juan?

The hottest day measured in San Juan between 1940 and 2025 was 12 July 2023, reaching 34.1 °C.

What is the coldest day in San Juan?

The coldest day measured in San Juan between 1940 and 2025 was 13 January 1941, at 10.1 °C.

Does it snow in San Juan?

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

Has the climate of San Juan warmed?

Yes: San Juan warmed by +0.8 °C between 1940 and 2025, a statistically significant trend.

What is the wettest day in San Juan?

The wettest day measured in San Juan between 1940 and 2025 was 22 May 1948, with 223 mm of rain in 24 hours.

What was the windiest day in San Juan?

The windiest day measured in San Juan between 1940 and 2025 was 23 September 1998, with winds reaching 41.4 km/h.

What is the warmest month in San Juan?

The warmest month in San Juan is August (23.2 °C on average); the coldest is January (20.1 °C).

How much does it rain in San Juan?

San Juan receives on average 911 mm of precipitation per year, spread over about 175 rainy days.

Is it sunny in San Juan?

San Juan gets on average 11.1 hours of sunshine per day, roughly 4,052 hours per year over 1940-2025.

Are there tropical nights in San Juan?

Yes: San Juan has on average 21 tropical nights per year (temperature staying above 20 °C), over 1940-2025.

What was the most extreme apparent temperature in San Juan?

In San Juan, between 1940 and 2025, the highest apparent temperature reached 38.0 °C on 12 July 2023, and the lowest was 7.7 °C on 2 March 1941.

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