Cardiff
September
Weather in Cardiff for September 2025
Your guide to Cardiff weather in September - trends and predictions
In general, the average temperature in Cardiff at the beginning of September is 20.4 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 15.7 °C by the end of September.
Cardiff in September brings notable rainfall, with an average of 18 rainy days and a total precipitation of 101.4 mm.
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Temperatures
Rain 🌧️
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12
Dry days
18
Rainy days
0
Snow days
18°/12°
Temperatures
23 km/h
Avg max wind
81 %
Avg humidity
Cardiff in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  20° | 2  20° | 3 20° | 4  20° | 5 20° | 6 21° | 7 22° |
| 8 21° | 9 21° | 10 19° | 11 17° | 12  15° | 13  16° | 14  16° |
| 15 19° | 16 18° | 17 18° | 18  19° | 19 20° | 20 19° | 21 18° |
| 22 17° | 23 16° | 24 17° | 25 16° | 26 16° | 27 15° | 28 15° |
| 29 15° | 30 16° |
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Temperatures trend during September in Cardiff
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 | 20° /13° | 2.5 mm | 5 | |
| 2 Sept. | Partly cloudy | 20° /12° | 0.3 mm | 5 | |
| 3 Sept. | Partly cloudy | 20° /13° | 1 mm | 5 | |
| 4 Sept. | Sunny | 20° /13° | 0.1 mm | 5 | |
| 5 Sept. | Sunny | 20° /13° | 10.8 mm | 5 | |
| 6 Sept. | Partly cloudy | 21° /15° | 4.4 mm | 5 | |
| 7 Sept. | Sunny | 22° /15° | 0.2 mm | 5 | |
| 8 Sept. | Partly cloudy | 21° /15° | 10.5 mm | 5 | |
| 9 Sept. | Sunny | 21° /13° | 0.7 mm | 6 | |
| 10 Sept. | Partly cloudy | 19° /12° | 0.9 mm | 5 | |
| 11 Sept. | Patchy rain possible | 17° /11° | 0.2 mm | 4 | |
| 12 Sept. | Mist | 15° /9° | 0.5 mm | 4 | |
| 13 Sept. | Cloudy | 16° /8° | 0 mm | 4 | |
| 14 Sept. | Overcast | 16° /10° | 0 mm | 5 | |
| 15 Sept. | Sunny | 19° /10° | 0 mm | 5 | |
| 16 Sept. | Light rain shower | 18° /11° | 0.7 mm | 5 | |
| 17 Sept. | Light rain shower | 18° /11° | 5.8 mm | 5 | |
| 18 Sept. | Light drizzle | 19° /12° | 0.8 mm | 5 | |
| 19 Sept. | Light rain shower | 20° /13° | 2.9 mm | 5 | |
| 20 Sept. | Light rain shower | 19° /12° | 10.2 mm | 5 | |
| 21 Sept. | Light rain shower | 18° /10° | 6.3 mm | 5 | |
| 22 Sept. | Light rain shower | 17° /10° | 4.5 mm | 4 | |
| 23 Sept. | Patchy rain possible | 16° /10° | 1.1 mm | 4 | |
| 24 Sept. | Light rain shower | 17° /12° | 5.4 mm | 4 | |
| 25 Sept. | Patchy rain possible | 16° /11° | 4.2 mm | 4 | |
| 26 Sept. | Light rain shower | 16° /11° | 6 mm | 4 | |
| 27 Sept. | Light rain shower | 15° /9° | 5.7 mm | 4 | |
| 28 Sept. | Light rain | 15° /9° | 2.8 mm | 4 | |
| 29 Sept. | Partly cloudy | 15° /9° | 8.4 mm | 4 | |
| 30 Sept. | Patchy rain possible | 16° /10° | 4.5 mm | 4 | |
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Important Notice
Our weather forecast for Cardiff 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 Cardiff forecast closer to your planned date for the most up-to-date weather information.
Cardiff in September - FAQ
What are the expected maximum and minimum temperatures in Cardiff during September?
Enjoy moderate daytime temperatures of up to 18° and cooler nights around 12°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Cardiff during September?
Significant rainfall exceeding 101.4 mm is expected in Cardiff during September, occurring over more than 18 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Cardiff during September?
The average wind speed in Cardiff during September is 23 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Cardiff
Explore the daily rainfall trends and prepare for Cardiffs September weather 💧
UV exposure in Cardiff during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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