Climate averages 1991–2020
Cayenne weather
in September.
A hot, fairly dry month: the 2nd warmest and the driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Cayenne: daytime highs average 31.3°C and nights cool to about 24.2°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 23 mm of rain on roughly 7 days, which makes September a fairly dry month (the driest month of the year). Daylight, from sunrise to sunset, lasts about 12 h 09 min on an average September day.
The nearest other city in this atlas is Paramaribo (330 km away). In September its highs average 31.0°C, about as warm as Cayenne, with 66 mm of rain.
From September to October, average highs rise by 0.1°C to 31.5°C, and monthly rainfall rises from 23 mm to 39 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
Cayenne climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 27.6°C23.3°C | 23.3°C | 244 | 26.6 | 11.912 h |
| February | 27.6°C23.5°C | 23.5°C | 205 | 22.5 | 12.012 h |
| March | 28.1°C23.8°C | 23.8°C | 173 | 23.9 | 12.112 h |
| April | 28.3°C23.8°C | 23.8°C | 257 | 25.0 | 12.212 h |
| May | 28.2°C23.6°C | 23.6°C | 411 | 29.1 | 12.312 h |
| June | 28.3°C23.2°C | 23.2°C | 343 | 28.5 | 12.412 h |
| July | 28.9°C23.2°C | 23.2°C | 186 | 24.8 | 12.412 h |
| August | 30.1°C23.7°C | 23.7°C | 67 | 13.9 | 12.312 h |
| September, selected | 31.3°C24.2°C | 24.2°C | 23 | 7.2 | 12.112 h |
| October | 31.5°C24.3°C | 24.3°C | 39 | 10.1 | 12.012 h |
| November | 30.1°C24.1°C | 24.1°C | 122 | 19.6 | 11.912 h |
| December | 28.4°C23.6°C | 23.6°C | 253 | 26.5 | 11.812 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
- Paramaribo in SeptemberSuriname · 330 kmHigh 31.0°C · Low 24.2°C · 66 mm rain
- Macapá in SeptemberBrazil · 563 kmHigh 31.2°C · Low 24.8°C · 26 mm rain
- Santana in SeptemberBrazil · 568 kmHigh 31.5°C · Low 24.7°C · 24 mm rain
- Georgetown in SeptemberGuyana · 676 kmHigh 29.1°C · Low 25.5°C · 96 mm rain
- Breves in SeptemberBrazil · 764 kmHigh 33.4°C · Low 24.5°C · 25 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 Cayenne) is explained once on the Cayenne year overview and on the Sources, method and limits page.