Cardiff
September
Weather in Cardiff for September 2026
Your guide to Cardiff weather in September - trends and predictions
Until now, September 2026 in Cardiff is slightly cooler than the historical average by 0.6 °C.
The forecast for the next days in Cardiff predicts temperatures to be around 20 °C, close to the historical average.
In general, the average temperature in Cardiff at the beginning of September is 19.9 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 16.1 °C by the end of September.
Cardiff in September brings notable rainfall, with an average of 16 rainy days and a total precipitation of 114.1 mm.
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Temperatures
Rain 🌧️
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14
Dry days
16
Rainy days
0
Snow days
17°/11°
Temperatures
24 km/h
Avg max wind
81 %
Avg humidity
Cardiff Weather September
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Temperatures trend during September in Cardiff
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September weather in Cardiff day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Light rain shower | 19° /12° | 3 mm | 4 | |
| 2 Sept. |  Partly cloudy | 20° /12° | 3 mm | 4 | |
| 3 Sept. | Light rain shower | 20° /13° | 6 mm | 4 | |
| 4 Sept. |  Sunny | 19° /12° | 1.8 mm | 4 | |
| 5 Sept. | Sunny | 19° /11° | 5.4 mm | 5 | |
| 6 Sept. |  Overcast | 22° /13° | 2.2 mm | 4 | |
| 7 Sept. | Patchy rain possible | 20° /14° | 1.6 mm | 4 | |
| 8 Sept. | Light rain shower | 20° /13° | 10.1 mm | 4 | |
| 9 Sept. | Sunny | 19° /12° | 1.4 mm | 5 | |
| 10 Sept. | Partly cloudy | 18° /11° | 3.8 mm | 4 | |
| 11 Sept. | Patchy rain possible | 18° /11° | 2 mm | 4 | |
| 12 Sept. | Patchy rain possible | 20° /11° | 0.2 mm | 3 | |
| 13 Sept. | Overcast | 21° /15° | 2.6 mm | 4.3 | |
| 14 Sept. | Sunny | 23° /15° | 0.7 mm | 4 | |
| 15 Sept. | Sunny | 19° /12° | 0.1 mm | 5 | |
| 16 Sept. | Patchy rain possible | 17° /10° | 0.5 mm | 4 | |
| 17 Sept. | Patchy rain possible | 17° /10° | 2.9 mm | 4 | |
| 18 Sept. | Sunny | 18° /8° | 0 mm | 5 | |
| 19 Sept. | Sunny | 21° /14° | 0.1 mm | 6 | |
| 20 Sept. | Sunny | 25° /11° | 0 mm | 6 | |
| 21 Sept. | Sunny | 23° /13° | 1.3 mm | 6 | |
| 22 Sept. | Sunny | 17° /11° | 5.3 mm | 5 | |
| 23 Sept. | Light rain shower | 17° /11° | 11.8 mm | 4 | |
| 24 Sept. | Patchy rain possible | 18° /12° | 5.8 mm | 5 | |
| 25 Sept. | Patchy rain possible | 17° /9° | 7 mm | 4 | |
| 26 Sept. | Light rain shower | 16° /10° | 4 mm | 4 | |
| 27 Sept. | Light rain shower | 15° /9° | 5.2 mm | 3 | |
| 28 Sept. |  Light rain | 16° /9° | 2.7 mm | 4 | |
| 29 Sept. | Partly cloudy | 15° /9° | 5.6 mm | 4 | |
| 30 Sept. | Patchy rain possible | 16° /9° | 3 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.
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Cardiff in September - FAQ
What are the expected maximum and minimum temperatures in Cardiff during September?
Enjoy moderate daytime temperatures of up to 17° and cooler nights around 11°. 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 114.1 mm is expected in Cardiff during September, occurring over more than 16 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 24 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 💧
Typically, Cardiff has 16 rainy days in September with a total of 114.1 mm of rainfall.
UV exposure in Cardiff during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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