Castries weather in August
In August, Castries has daytime highs averaging 29 °C, nights around 25 °C, with 20 wet days, and a sea temperature of 29 °C. Figures are 1991–2020 climate normals.
- 29.0°C Average high
- 25.1°C Average low
- 20days Wet days
- 101mm Rainfall
- 28.7°C Sea temperature
- 13h Daylight
Daily temperatures through August
How August develops
Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.
| Days | Avg high | Avg low | Chance of rain |
|---|---|---|---|
| 1–10 August | 28.9 °C | 25.0 °C | 69 % |
| 11–20 August | 29.0 °C | 25.1 °C | 67 % |
| 21–31 August | 29.1 °C | 25.2 °C | 63 % |
- Rain is most likely over days 1–10 of August (69 % of days) and least likely over days 21–31 (63 %).
What to expect
| Measure | Typical August | Share of the month |
|---|---|---|
| Days above 25 °C | 31 of 31 | 100 % |
| Days above 30 °C | 2.7 of 31 | 9 % |
| Days below 0 °C | 0 of 31 | 0 % |
| Days with more than 1 mm rain | 20 of 31 | 66 % |
Conditions in August
| Measure | Average |
|---|---|
| Mean temperature | 27 °C |
| Record high (1991–2020) | 31 °C |
| Record low (1991–2020) | 23 °C |
| Relative humidity | 79 % |
| Wind speed | 22 km/h |
| Cloud cover | 55 % |
August compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| June | 29.0 °C | 68 mm | 63 % |
| July | 28.8 °C | 89 mm | 54 % |
| August | 29.0 °C | 101 mm | 55 % |
| September | 29.2 °C | 105 mm | 62 % |
| October | 28.7 °C | 119 mm | 61 % |
See all twelve months for Castries
- August is the 3rd warmest month here.
- It is the 9th driest month of the year.
- It ranks 8th for least cloud cover.
- Days last about 13 hours from sunrise to sunset.
- It rains on 20 of 31 days — 66 % of the month.
- Nights are about 3.9 °C cooler than the middle of the day.
- The hottest August day on record since 1991 reached 31 °C, 2.4 °C above the usual daytime high.
- Beach score: 70 / 100 — see how this is calculated.
QuestionsAugust in Castries, answered
How warm is Castries in August?
Daily highs average 29 °C and nights fall to about 25 °C, a spread of 3.9 °C between afternoon and dawn. That makes August the 2nd warmest month of the year here.
Does it rain much in Castries in August?
August averages 101 mm of rain, spread over about 20 of the 31 days — 66 % of the month. Cloud cover averages 55 % of the sky.
Is the sea warm enough to swim in August?
The sea averages 29 °C off Castries in August. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.
How long are the days in August?
Castries averages 13 hours between sunrise and sunset in August. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.