Portmore climate — normals and trends
Portmore (Jamaica) has a tropical savanna climate (Aw) under the Köppen-Geiger classification. Its mean annual temperature is 25.1 °C and it receives 858 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 (26.6 °C on average) and the coldest is January (23.5 °C). Rainfall peaks in October.
Portmore averages 0 frost days, 39 hot days (≥ 30 °C) and 151 rainy days per year.
Portmore has warmed by +1.7 °C between 1940 and 2025, or +0.19 °C per decade. This trend is statistically significant.
The hottest day of the period reached 33.8 °C (on 20 August 2023) and the coldest 15.3 °C (on 10 January 1956).
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
PortmoreSaint Catherine Parish
- coords
- 17.97°, -76.89°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
25.1°C
Average daily high
28.0°C
Average daily low
22.8°C
Annual rainfall
858mm
Sunshine / day
11.1h
Mean relative humidity
80%
Average peak wind
16.7km/h
Seasonal range
3.1°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
39 d/yr
Rainy days (≥ 1 mm)
151 d/yr
Annual snowfall
0.0 cm
Average feels-like high
31.6 °C
Average feels-like low
25.9 °C
Average peak gust
34.8 km/h
Tropical nights (≥ 20 °C)
353 d/yr
Solar radiation
20.4 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.7 °C
since 1940
+0.2 °C per decade · r² = 0.71 · 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
33.8 °C
20 August 2023
Coldest day
15.3 °C
10 January 1956
Wettest day
216 mm
11 September 2004
Windiest day
86.1 km/h
10 September 2004
Strongest gust
162.4 km/h
19 August 2007
Hottest feels-like
39.0 °C
20 August 2023
Coldest feels-like
14.9 °C
10 January 1956
Sunniest day
12.7 h
18 July 2025
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 | 27.5 °C | +0.9 °C | 9 mm | -12 mm |
| Feb | 27.4 °C | +0.7 °C | 16 mm | -5 mm |
| Mar | 28.0 °C | +0.8 °C | 29 mm | -0 mm |
| Apr | 28.0 °C | +0.1 °C | 78 mm | +26 mm |
| May | 29.1 °C | +0.9 °C | 58 mm | -57 mm |
| Jun | 29.7 °C | +1.0 °C | 29 mm | -56 mm |
| Jul | 31.0 °C | +1.4 °C | 20 mm | -40 mm |
| Aug | 31.6 °C | +1.9 °C | 42 mm | -47 mm |
| Sep | 31.1 °C | +2.1 °C | 103 mm | -30 mm |
| Oct | 29.0 °C | +0.8 °C | 544 mm | +394 mm |
| Nov | 28.6 °C | +1.1 °C | 32 mm | -41 mm |
| Dec | 27.9 °C | +1.0 °C | 14 mm | -16 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 Portmore?
Portmore has a tropical savanna climate (Köppen Aw). Over 1940-2025, the average annual temperature is 25.1 °C and it receives 858 mm of precipitation per year.
What is the hottest day ever recorded in Portmore?
The hottest day measured in Portmore between 1940 and 2025 was 20 August 2023, reaching 33.8 °C.
What is the coldest day in Portmore?
The coldest day measured in Portmore between 1940 and 2025 was 10 January 1956, at 15.3 °C.
Does it snow in Portmore?
Almost never: Portmore sees virtually no snow, with about 0 frost days per year.
Has the climate of Portmore warmed?
Yes: Portmore warmed by +1.7 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Portmore?
The wettest day measured in Portmore between 1940 and 2025 was 11 September 2004, with 216 mm of rain in 24 hours.
What was the windiest day in Portmore?
The windiest day measured in Portmore between 1940 and 2025 was 10 September 2004, with winds reaching 86.1 km/h.
What is the warmest month in Portmore?
The warmest month in Portmore is July (26.6 °C on average); the coldest is January (23.5 °C).
How much does it rain in Portmore?
Portmore receives on average 858 mm of precipitation per year, spread over about 151 rainy days.
Is it sunny in Portmore?
Portmore gets on average 11.1 hours of sunshine per day, roughly 4,052 hours per year over 1940-2025.
Are there tropical nights in Portmore?
Yes: Portmore has on average 353 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Portmore?
In Portmore, between 1940 and 2025, the highest apparent temperature reached 39.0 °C on 20 August 2023, and the lowest was 14.9 °C on 10 January 1956.
Compare Portmore with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Portmore