September
Weather in St Helier for September 2025
Your guide to St Helier weather in September - trends and predictions
In general, the average temperature in St Helier at the beginning of September is 19.6 °C. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 17.3 °C by the end of September.
The climate of St Helier in September is notably wet, with an average of 13 rainy days.
Is September a good time to visit St Helier? check out the best time to travel to St Helier page.
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17
Dry days
13
Rainy days
0
Snow days
19°/17°
Temperatures
30 km/h
Avg max wind
79 %
Avg humidity
St Helier in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  18° | 2  19° | 3 20° | 4  20° | 5 20° | 6 20° | 7 20° |
| 8 19° | 9 20° | 10  19° | 11  18° | 12 17° | 13  17° | 14 17° |
| 15 19° | 16 19° | 17 19° | 18 19° | 19 19° | 20  19° | 21 17° |
| 22  17° | 23 16° | 24 17° | 25 17° | 26 17° | 27 17° | 28 17° |
| 29 18° | 30 18° |
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Temperatures trend during September in St Helier
See the weather trend as well as the moving average line
September weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. | Light rain shower | 18° /17° | 14.5 mm | 4 | |
| 2 Sept. | Partly cloudy | 19° /16° | 1.2 mm | 5 | |
| 3 Sept. | Partly cloudy | 20° /17° | 0.7 mm | 5 | |
| 4 Sept. | Sunny | 20° /17° | 0.7 mm | 5 | |
| 5 Sept. | Sunny | 20° /17° | 2.6 mm | 5 | |
| 6 Sept. | Partly cloudy | 20° /17° | 0 mm | 5 | |
| 7 Sept. | Sunny | 20° /17° | 5.1 mm | 5 | |
| 8 Sept. | Partly cloudy | 19° /17° | 6 mm | 5 | |
| 9 Sept. | Patchy rain possible | 20° /17° | 0.7 mm | 5 | |
| 10 Sept. | Patchy light rain with thunder | 19° /17° | 7.8 mm | 5 | |
| 11 Sept. | Cloudy | 18° /16° | 1.1 mm | 4 | |
| 12 Sept. | Partly cloudy | 17° /15° | 1.3 mm | 4 | |
| 13 Sept. | Overcast | 17° /15° | 0.2 mm | 4 | |
| 14 Sept. | Sunny | 17° /15° | 0 mm | 5 | |
| 15 Sept. | Sunny | 19° /15° | 0 mm | 6 | |
| 16 Sept. | Patchy rain possible | 19° /17° | 0.7 mm | 5 | |
| 17 Sept. | Light rain shower | 19° /17° | 2.9 mm | 5 | |
| 18 Sept. | Light rain shower | 19° /17° | 0.9 mm | 5 | |
| 19 Sept. | Patchy rain possible | 19° /17° | 0.2 mm | 5 | |
| 20 Sept. | Moderate or heavy rain shower | 19° /16° | 10.5 mm | 4 | |
| 21 Sept. | Light rain shower | 17° /15° | 5.1 mm | 4 | |
| 22 Sept. | Patchy light drizzle | 17° /15° | 3.2 mm | 4 | |
| 23 Sept. | Patchy rain possible | 16° /14° | 7.4 mm | 4 | |
| 24 Sept. | Partly cloudy | 17° /15° | 2.3 mm | 5 | |
| 25 Sept. | Overcast | 17° /15° | 4.4 mm | 4 | |
| 26 Sept. | Patchy light drizzle | 17° /15° | 3.7 mm | 4 | |
| 27 Sept. | Patchy rain possible | 17° /14° | 5.1 mm | 4 | |
| 28 Sept. | Patchy rain possible | 17° /14° | 0.7 mm | 4 | |
| 29 Sept. | Patchy rain possible | 18° /14° | 1.1 mm | 4 | |
| 30 Sept. | Sunny | 18° /15° | 1.9 mm | 5 | |
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Important Notice
Our weather forecast for St Helier in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the St Helier forecast closer to your planned date for the most up-to-date weather information.
St Helier in September - FAQ
What are the expected maximum and minimum temperatures in St Helier during September?
During September, expect a variety of temperatures with highs around 19° and lows near 17°, suitable for diverse activities and preferences.
How much rainfall should be expected in St Helier during September?
Moderate rainfall is anticipated in St Helier during September, with a total of 81.9 mm spread over approximately 13 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in St Helier during September?
The average wind speed in St Helier during September is 30 km/h, suggesting breezy to windy conditions, depending on your activities.
What to pack to St Helier in September?
As you prepare for your trip to St Helier in September, it's important to consider the typical weather patterns for the time of year. Below is a carefully tailored packing list to ensure that your time in St Helier, during September, is comfortable and enjoyable, regardless of the weather conditions.
- Clothing
- Layered Clothing: Light sweaters, long-sleeve shirts, light jackets, and comfortable pants
- Rain Gear: Lightweight, waterproof clothing
- Footwear
- Waterproof Shoes
- Accessories
- Umbrellas/Raincoats: For rainy days
September rainfall patterns in St Helier
Explore the daily rainfall trends and prepare for St Heliers September weather 💧
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