Arecibo climate — normals and trends
Arecibo (Puerto Rico) has a tropical savanna climate (Aw) under the Köppen-Geiger classification. Its mean annual temperature is 25.2 °C and it receives 1,142 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 (26.7 °C on average) and the coldest is January (23.6 °C). Rainfall peaks in May.
Arecibo averages 0 frost days, 56 hot days (≥ 30 °C) and 191 rainy days per year.
Arecibo has warmed by +1.3 °C between 1940 and 2025, or +0.15 °C per decade. This trend is statistically significant.
The hottest day of the period reached 33.1 °C (on 10 September 1997) and the coldest 17.5 °C (on 12 March 1951).
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
AreciboArecibo
- coords
- 18.47°, -66.72°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
25.2°C
Average daily high
28.2°C
Average daily low
23.0°C
Annual rainfall
1,142mm
Sunshine / day
11.3h
Mean relative humidity
81%
Average peak wind
18.5km/h
Seasonal range
3.1°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
56 d/yr
Rainy days (≥ 1 mm)
191 d/yr
Annual snowfall
0.0 cm
Average feels-like high
31.8 °C
Average feels-like low
25.8 °C
Average peak gust
36.3 km/h
Tropical nights (≥ 20 °C)
358 d/yr
Solar radiation
20.5 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.3 °C
since 1940
+0.2 °C per decade · r² = 0.70 · 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
33.1 °C
10 September 1997
Coldest day
17.5 °C
12 March 1951
Wettest day
236 mm
20 September 2017
Windiest day
87.6 km/h
20 September 2017
Strongest gust
146.5 km/h
20 September 2017
Hottest feels-like
41.1 °C
9 October 2024
Coldest feels-like
16.3 °C
6 February 1955
Sunniest day
13.0 h
3 June 1940
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 | 27.2 °C | +0.6 °C | 36 mm | -5 mm |
| Feb | 27.6 °C | +0.8 °C | 37 mm | -5 mm |
| Mar | 28.0 °C | +0.7 °C | 53 mm | +1 mm |
| Apr | 27.7 °C | -0.1 °C | 207 mm | +96 mm |
| May | 28.8 °C | +0.3 °C | 191 mm | +22 mm |
| Jun | 29.6 °C | +0.1 °C | 23 mm | -67 mm |
| Jul | 30.2 °C | +0.6 °C | 36 mm | -41 mm |
| Aug | 30.2 °C | +0.4 °C | 109 mm | +4 mm |
| Sep | 30.3 °C | +0.8 °C | 207 mm | +60 mm |
| Oct | 30.1 °C | +1.1 °C | 105 mm | -45 mm |
| Nov | 28.6 °C | +0.9 °C | 53 mm | -53 mm |
| Dec | 27.9 °C | +1.0 °C | 23 mm | -28 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 Arecibo?
Arecibo has a tropical savanna climate (Köppen Aw). Over 1940-2025, the average annual temperature is 25.2 °C and it receives 1,142 mm of precipitation per year.
What is the hottest day ever recorded in Arecibo?
The hottest day measured in Arecibo between 1940 and 2025 was 10 September 1997, reaching 33.1 °C.
What is the coldest day in Arecibo?
The coldest day measured in Arecibo between 1940 and 2025 was 12 March 1951, at 17.5 °C.
Does it snow in Arecibo?
Almost never: Arecibo sees virtually no snow, with about 0 frost days per year.
Has the climate of Arecibo warmed?
Yes: Arecibo warmed by +1.3 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Arecibo?
The wettest day measured in Arecibo between 1940 and 2025 was 20 September 2017, with 236 mm of rain in 24 hours.
What was the windiest day in Arecibo?
The windiest day measured in Arecibo between 1940 and 2025 was 20 September 2017, with winds reaching 87.6 km/h.
What is the warmest month in Arecibo?
The warmest month in Arecibo is August (26.7 °C on average); the coldest is January (23.6 °C).
How much does it rain in Arecibo?
Arecibo receives on average 1,142 mm of precipitation per year, spread over about 191 rainy days.
Is it sunny in Arecibo?
Arecibo gets on average 11.3 hours of sunshine per day, roughly 4,125 hours per year over 1940-2025.
Are there tropical nights in Arecibo?
Yes: Arecibo has on average 358 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Arecibo?
In Arecibo, between 1940 and 2025, the highest apparent temperature reached 41.1 °C on 9 October 2024, and the lowest was 16.3 °C on 6 February 1955.
Compare Arecibo with another city
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Nearby cities
The climate around Arecibo