Click on a day for an hourly weather forecast
The temperatures in Castries during September are extremely high, between 27°C and hot as 30°C, drinking water regularly is advisable.
You can expect rain for roughly half of the month of September in Castries. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Castries in September 2025.
If you’re planning to visit Castries in the near future, we highly recommend that you review the 14 day weather forecast for Castries before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 28° / 25° | 1 | 30 | 0 | 54 mm | Perfect | Castries in January |
| February | 27° / 25° | 1 | 27 | 0 | 44 mm | Perfect | Castries in February |
| March | 28° / 25° | 1 | 30 | 0 | 47 mm | Perfect | Castries in March |
| April | 28° / 26° | 2 | 28 | 0 | 61 mm | Perfect | Castries in April |
| May | 29° / 26° | 2 | 29 | 0 | 72 mm | Good | Castries in May |
| June | 29° / 27° | 4 | 26 | 0 | 110 mm | Good | Castries in June |
| July | 29° / 27° | 7 | 24 | 0 | 146 mm | Ok | Castries in July |
| August | 30° / 27° | 7 | 24 | 0 | 168 mm | Ok | Castries in August |
| September | 30° / 27° | 8 | 22 | 0 | 157 mm | Ok | Castries in September |
| October | 30° / 27° | 6 | 25 | 0 | 161 mm | Good | Castries in October |
| November | 29° / 26° | 5 | 25 | 0 | 124 mm | Good | Castries in November |
| December | 28° / 26° | 2 | 29 | 0 | 68 mm | Perfect | Castries in December |