Osu climate — normals and trends
Osu (Ghana) has a hot semi-arid climate (BSh) under the Köppen-Geiger classification. Its mean annual temperature is 26.0 °C and it receives 733 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 March (27.4 °C on average) and the coldest is August (23.6 °C). Rainfall peaks in June.
Osu averages 0 frost days, 4 hot days (≥ 30 °C) and 153 rainy days per year.
Osu has warmed by +0.9 °C between 1940 and 2025, or +0.11 °C per decade. This trend is statistically significant.
The hottest day of the period reached 31.2 °C (on 12 April 1952) and the coldest 20.5 °C (on 10 August 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
OsuGreater Accra
- coords
- 5.56°, -0.19°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
26.0°C
Average daily high
27.2°C
Average daily low
24.9°C
Annual rainfall
733mm
Sunshine / day
10.7h
Mean relative humidity
85%
Average peak wind
21.3km/h
Seasonal range
3.8°C
Frost days (< 0 °C)
0 d/yr
Hot days (≥ 30 °C)
4 d/yr
Rainy days (≥ 1 mm)
153 d/yr
Annual snowfall
0.0 cm
Average feels-like high
31.7 °C
Average feels-like low
28.5 °C
Average peak gust
30.9 km/h
Tropical nights (≥ 20 °C)
365 d/yr
Solar radiation
18.9 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+0.9 °C
since 1940
+0.1 °C per decade · r² = 0.57 · 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
31.2 °C
12 April 1952
Coldest day
20.5 °C
10 August 1956
Wettest day
193 mm
10 September 1987
Windiest day
37.5 km/h
15 April 1963
Strongest gust
50.8 km/h
15 April 1963
Hottest feels-like
38.2 °C
10 April 2024
Coldest feels-like
20.8 °C
8 January 1957
Sunniest day
12.0 h
2 April 1940
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 | 28.8 °C | +0.7 °C | 8 mm | -7 mm |
| Feb | 28.9 °C | +0.3 °C | 11 mm | -11 mm |
| Mar | 29.3 °C | +0.4 °C | 7 mm | -33 mm |
| Apr | 29.2 °C | +0.4 °C | 34 mm | -28 mm |
| May | 28.7 °C | +0.7 °C | 110 mm | -26 mm |
| Jun | 27.3 °C | +0.8 °C | 138 mm | -36 mm |
| Jul | 25.0 °C | -0.1 °C | 25 mm | -45 mm |
| Aug | 24.2 °C | -0.2 °C | 34 mm | +4 mm |
| Sep | 25.8 °C | +0.5 °C | 97 mm | +55 mm |
| Oct | 27.1 °C | +0.4 °C | 111 mm | +56 mm |
| Nov | 28.2 °C | +0.4 °C | 32 mm | -22 mm |
| Dec | 28.7 °C | +0.5 °C | 44 mm | +12 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 Osu?
Osu has a hot semi-arid climate (Köppen BSh). Over 1940-2025, the average annual temperature is 26.0 °C and it receives 733 mm of precipitation per year.
What is the hottest day ever recorded in Osu?
The hottest day measured in Osu between 1940 and 2025 was 12 April 1952, reaching 31.2 °C.
What is the coldest day in Osu?
The coldest day measured in Osu between 1940 and 2025 was 10 August 1956, at 20.5 °C.
Does it snow in Osu?
Almost never: Osu sees virtually no snow, with about 0 frost days per year.
Has the climate of Osu warmed?
Yes: Osu warmed by +0.9 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Osu?
The wettest day measured in Osu between 1940 and 2025 was 10 September 1987, with 193 mm of rain in 24 hours.
What was the windiest day in Osu?
The windiest day measured in Osu between 1940 and 2025 was 15 April 1963, with winds reaching 37.5 km/h.
What is the warmest month in Osu?
The warmest month in Osu is March (27.4 °C on average); the coldest is August (23.6 °C).
How much does it rain in Osu?
Osu receives on average 733 mm of precipitation per year, spread over about 153 rainy days.
Is it sunny in Osu?
Osu gets on average 10.7 hours of sunshine per day, roughly 3,905 hours per year over 1940-2025.
Are there tropical nights in Osu?
Yes: Osu has on average 365 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Osu?
In Osu, between 1940 and 2025, the highest apparent temperature reached 38.2 °C on 10 April 2024, and the lowest was 20.8 °C on 8 January 1957.
Compare Osu with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Osu