Waterloo climate — normals and trends
Waterloo (Sierra Leone) has a tropical monsoon climate (Am) under the Köppen-Geiger classification. Its mean annual temperature is 25.9 °C and it receives 3,137 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 (27.1 °C on average) and the coldest is August (24.6 °C). Rainfall peaks in August.
Waterloo averages 0 frost days, 59 hot days (≥ 30 °C) and 245 rainy days per year.
Waterloo has warmed by +1.1 °C between 1940 and 2025, or +0.13 °C per decade. This trend is statistically significant.
The hottest day of the period reached 34.4 °C (on 21 February 2016) and the coldest 20.3 °C (on 9 January 1957).
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
WaterlooWestern Area
- coords
- 8.34°, -13.07°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
25.9°C
Average daily high
28.3°C
Average daily low
24.1°C
Annual rainfall
3,137mm
Sunshine / day
9.7h
Mean relative humidity
85%
Average peak wind
13.3km/h
Seasonal range
2.5°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
59 d/yr
Rainy days (≥ 1 mm)
245 d/yr
Annual snowfall
0.0 cm
Average feels-like high
33.4 °C
Average feels-like low
28.2 °C
Average peak gust
27.7 km/h
Tropical nights (≥ 20 °C)
365 d/yr
Solar radiation
17.2 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.1 °C
since 1940
+0.1 °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
34.4 °C
21 February 2016
Coldest day
20.3 °C
9 January 1957
Wettest day
263 mm
18 June 2024
Windiest day
33.3 km/h
26 July 1988
Strongest gust
62.3 km/h
26 July 1988
Hottest feels-like
40.6 °C
9 March 2024
Coldest feels-like
18.1 °C
3 March 1943
Sunniest day
12.0 h
31 May 1959
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 | 31.0 °C | +1.6 °C | 5 mm | -17 mm |
| Feb | 31.4 °C | +1.6 °C | 0 mm | -16 mm |
| Mar | 30.8 °C | +0.8 °C | 2 mm | -26 mm |
| Apr | 30.8 °C | +1.0 °C | 44 mm | -26 mm |
| May | 29.4 °C | +0.6 °C | 222 mm | -16 mm |
| Jun | 28.4 °C | +0.7 °C | 364 mm | -53 mm |
| Jul | 26.6 °C | +0.1 °C | 892 mm | +249 mm |
| Aug | 26.4 °C | +0.2 °C | 794 mm | +93 mm |
| Sep | 26.9 °C | +0.1 °C | 793 mm | +277 mm |
| Oct | 28.3 °C | +0.6 °C | 262 mm | -26 mm |
| Nov | 28.6 °C | +0.3 °C | 164 mm | +19 mm |
| Dec | 28.9 °C | +0.1 °C | 86 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 Waterloo?
Waterloo has a tropical monsoon climate (Köppen Am). Over 1940-2025, the average annual temperature is 25.9 °C and it receives 3,137 mm of precipitation per year.
What is the hottest day ever recorded in Waterloo?
The hottest day measured in Waterloo between 1940 and 2025 was 21 February 2016, reaching 34.4 °C.
What is the coldest day in Waterloo?
The coldest day measured in Waterloo between 1940 and 2025 was 9 January 1957, at 20.3 °C.
Does it snow in Waterloo?
Almost never: Waterloo sees virtually no snow, with about 0 frost days per year.
Has the climate of Waterloo warmed?
Yes: Waterloo warmed by +1.1 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Waterloo?
The wettest day measured in Waterloo between 1940 and 2025 was 18 June 2024, with 263 mm of rain in 24 hours.
What was the windiest day in Waterloo?
The windiest day measured in Waterloo between 1940 and 2025 was 26 July 1988, with winds reaching 33.3 km/h.
What is the warmest month in Waterloo?
The warmest month in Waterloo is April (27.1 °C on average); the coldest is August (24.6 °C).
How much does it rain in Waterloo?
Waterloo receives on average 3,137 mm of precipitation per year, spread over about 245 rainy days.
Is it sunny in Waterloo?
Waterloo gets on average 9.7 hours of sunshine per day, roughly 3,540 hours per year over 1940-2025.
Are there tropical nights in Waterloo?
Yes: Waterloo has on average 365 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Waterloo?
In Waterloo, between 1940 and 2025, the highest apparent temperature reached 40.6 °C on 9 March 2024, and the lowest was 18.1 °C on 3 March 1943.
Compare Waterloo with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Waterloo