Saint Helier weather in August
Temperature, sea and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Excellent
Best time to visit: June – September
What is the weather like in Saint Helier in August?
In August, Saint Helier is mild: daytime highs average 19 °C, and nights cool down to about 16 °C. The sea averages 18.0 °C – bracing, so a wetsuit helps for longer swims. The sun shines for around 7 hours a day. Rain is frequent, with about 11 rainy days and 60 mm in total. All in all, August is an excellent month for a holiday in Saint Helier.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 85 | 80 | 77 |
| Day | 18° | 19° | 18° |
| Night | 16° | 16° | 15° |
| Sea | 17° | 18° | 18° |
| Sun | 8 h | 7 h | 6 h |
| Rain days | 10 | 11 | 10 |
More details for August
- Daylight
- 14 h 28 min05:59 – 20:27
- UV index
- 6 · highclear sky, noon (estimate)All months
- Muggy days
- 1 daydew point 18 °C or moreAll months
- Wind
- 23 km/haverage daily peakAll months
- Cloud cover
- 59 %on averageAll months
- Hot days
- 0 days30 °C or more
- Time zone
- UTC+1Europe/Jersey
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %70 %
- Few rainy daysweight 30 %52 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in August
- Wetsuit for longer swims
- Sunscreen
- Sunglasses & sun hat
- Rain jacket or umbrella
Saint Helier in August: quick answers
Is Saint Helier hot in August?
No. In August, Saint Helier is mild: daytime highs average 19 °C and nights drop to about 16 °C.
Can you swim in Saint Helier in August?
Only if you don't mind cold water: in August the sea averages just 18.0 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Saint Helier in August?
Rain is frequent, with about 11 rainy days and 60 mm in total.
Saint Helier month by month
The whole year in Saint HelierAll destinations: JerseyWhere to go in AugustSea temperature in August
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences