Climate averages 1991–2020
Roseau weather
by month.
See how the year changes. September has the highest average daily maximum; February (tied with March) has the lowest average monthly rainfall.
Pleasant-weather months by our simple rule: FebruaryMarch
Long-term climate patterns, not a forecast for a particular trip.
Across the year Roseau averages a daytime high of 27.3°C and a nighttime low of 25.2°C, with about 744 mm of rain on roughly 157 days. September is the warmest month (average high 28.3°C) and February (tied with January) the coolest (25.9°C). October is the wettest month with 118 mm; February (tied with March) is the driest with 19 mm.
Months with pleasant weather by a simple rule (average high between 18°C and 29°C, average low of at least 5°C and at most 8 rain days): February and March. This looks at temperature and rain only, not humidity, wind, sea temperature or crowds.
The annual picture
A year in Roseau
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
Roseau climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 25.9°C24.2°C | 24.2°C | 31 | 12.0 | 11.311 h |
| February | 25.9°C24.0°C | 24.0°C | 19 | 7.0 | 11.612 h |
| March | 26.3°C24.2°C | 24.2°C | 19 | 6.9 | 12.012 h |
| April | 27.0°C24.7°C | 24.7°C | 29 | 8.3 | 12.512 h |
| May | 27.7°C25.5°C | 25.5°C | 44 | 10.2 | 12.813 h |
| June | 27.9°C25.9°C | 25.9°C | 47 | 10.5 | 13.013 h |
| July | 28.0°C25.8°C | 25.8°C | 76 | 16.4 | 12.913 h |
| August | 28.2°C26.0°C | 26.0°C | 99 | 18.4 | 12.613 h |
| September | 28.3°C26.2°C | 26.2°C | 113 | 17.1 | 12.212 h |
| October | 28.0°C25.9°C | 25.9°C | 118 | 19.1 | 11.812 h |
| November | 27.3°C25.4°C | 25.4°C | 101 | 17.1 | 11.411 h |
| December | 26.5°C24.8°C | 24.8°C | 48 | 14.3 | 11.211 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
Nearby cities
- Fort-de-FranceMartinique · 85 kmHigh 28.1°C · Low 25.3°C · 984 mm rain a year
- Basse-TerreGuadeloupe · 86 kmHigh 28.9°C · Low 25.6°C · 679 mm rain a year
- CastriesSaint Lucia · 151 kmHigh 28.2°C · Low 24.4°C · 776 mm rain a year
- Saint John’sAntigua and Barbuda · 208 kmHigh 27.6°C · Low 25.2°C · 817 mm rain a year
- KingstownSaint Vincent and the Grenadines · 239 kmHigh 27.9°C · Low 25.9°C · 1,003 mm rain a year
- BasseterreSaint Kitts and Nevis · 264 kmHigh 27.3°C · Low 25.2°C · 778 mm rain a year
- BridgetownBarbados · 310 kmHigh 27.7°C · Low 25.5°C · 968 mm rain a year
- Saint George'sGrenada · 363 kmHigh 27.6°C · Low 25.7°C · 1,135 mm rain a year
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 limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC-4, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at 15.30°, -61.30° (9 km from the city centre), adjusted up by 1.4°C for the difference between the city's elevation (11 m) and the cell's (221 m). Rain comes from the 0.25° cell at 15.25°, -61.50°. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.