Climate averages 1991–2020
Koidu weather
in September.
A warm, very wet month: the 10th warmest and the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Koidu: daytime highs average 27.3°C and nights cool to about 21.4°C. By daytime temperature it is the 10th warmest of the 12 months.
Expect about 422 mm of rain on roughly 29 days, which makes September a very wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 12 h 11 min on an average September day.
The nearest other city in this atlas is Kenema (89 km away). In September its highs average 27.9°C, 0.6°C warmer than Koidu, with 395 mm of rain.
Among the 5 cities listed in Sierra Leone, Koidu ranks 4th of 5 for the warmest September highs and 3rd of 5 for the driest September (rainfall, lowest first). The mean September high of those 5 cities is 27.6°C; Koidu is 0.3°C cooler than that mean.
From September to October, average highs rise by 0.9°C to 28.2°C, and monthly rainfall falls from 422 mm to 322 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Koidu climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 32.1°C20.4°C | 20.4°C | 11 | 2.4 | 11.712 h |
| February | 33.6°C21.9°C | 21.9°C | 14 | 2.9 | 11.812 h |
| March | 33.1°C23.1°C | 23.1°C | 63 | 10.3 | 12.112 h |
| April | 31.3°C23.2°C | 23.2°C | 105 | 15.7 | 12.312 h |
| May | 29.4°C22.7°C | 22.7°C | 235 | 25.4 | 12.513 h |
| June | 28.1°C21.9°C | 21.9°C | 335 | 28.0 | 12.613 h |
| July | 26.7°C21.2°C | 21.2°C | 369 | 29.3 | 12.613 h |
| August | 26.3°C21.1°C | 21.1°C | 419 | 29.7 | 12.412 h |
| September, selected | 27.3°C21.4°C | 21.4°C | 422 | 28.8 | 12.212 h |
| October | 28.2°C21.4°C | 21.4°C | 322 | 29.5 | 11.912 h |
| November | 28.5°C21.5°C | 21.5°C | 129 | 16.4 | 11.712 h |
| December | 29.9°C20.6°C | 20.6°C | 16 | 3.1 | 11.612 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Kenema in SeptemberSierra Leone · 89 kmHigh 27.9°C · Low 22.0°C · 395 mm rain
- Gueckedou in SeptemberGuinea · 93 kmHigh 27.5°C · Low 21.2°C · 351 mm rain
- Kissidougou in SeptemberGuinea · 113 kmHigh 27.6°C · Low 20.7°C · 323 mm rain
- Bo in SeptemberSierra Leone · 113 kmHigh 28.1°C · Low 21.9°C · 433 mm rain
- Makeni in SeptemberSierra Leone · 121 kmHigh 28.4°C · Low 22.4°C · 413 mm rain
- Faranah in SeptemberGuinea · 157 kmHigh 28.5°C · Low 21.3°C · 289 mm rain
- Mamou in SeptemberGuinea · 228 kmHigh 26.8°C · Low 20.0°C · 334 mm rain
- Gbarnga in SeptemberLiberia · 247 kmHigh 27.7°C · Low 21.9°C · 309 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Koidu) is explained once on the Koidu year overview and on the Sources, method and limits page.