Belfast
September
Weather in Belfast for September 2026
Your guide to Belfast weather in September - trends and predictions
Until now, September 2026 in Belfast is slightly cooler than the historical average by 0.9 °C.
The forecast for the next days in Belfast predicts temperatures to be around 17 °C, close to the historical average.
In general, the average temperature in Belfast at the beginning of September is 18 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 14.1 °C by the end of September.
Belfast experiences heavy rainfall in September, with over 20 rainy days and an average total precipitation 109.1 mm.
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Temperatures
Rain 🌧️
More
8
Dry days
22
Rainy days
0
Snow days
15°/8°
Temperatures
23 km/h
Avg max wind
84 %
Avg humidity
Belfast Weather September
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Temperatures trend during September in Belfast
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September weather in Belfast day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. |  Patchy rain possible | 17° /10° | 2.8 mm | 3 | |
| 2 Sept. | Light rain shower | 18° /10° | 3.1 mm | 3 | |
| 3 Sept. | Light rain shower | 17° /10° | 4.9 mm | 4 | |
| 4 Sept. | Patchy rain possible | 17° /9° | 1.6 mm | 4 | |
| 5 Sept. |  Overcast | 18° /9° | 0 mm | 4 | |
| 6 Sept. |  Partly cloudy | 20° /11° | 0.3 mm | 4 | |
| 7 Sept. | Patchy rain possible | 19° /11° | 2.4 mm | 4 | |
| 8 Sept. | Partly cloudy | 18° /9° | 0.7 mm | 4 | |
| 9 Sept. | Overcast | 17° /9° | 0.6 mm | 4 | |
| 10 Sept. |  Moderate or heavy rain shower | 17° /10° | 7.3 mm | 3 | |
| 11 Sept. | Light rain shower | 15° /8° | 2.6 mm | 3 | |
| 12 Sept. | Patchy rain possible | 19° /11° | 25.1 mm | 3.2 | |
| 13 Sept. | Patchy rain possible | 19° /13° | 0.2 mm | 3.1 | |
| 14 Sept. | Overcast | 21° /14° | 15 mm | 2.7 | |
| 15 Sept. | Patchy rain possible | 16° /11° | 2.7 mm | 4 | |
| 16 Sept. | Patchy rain possible | 15° /9° | 0.8 mm | 4 | |
| 17 Sept. | Patchy rain possible | 15° /9° | 1.5 mm | 3 | |
| 18 Sept. | Overcast | 16° /8° | 0 mm | 4 | |
| 19 Sept. |  Sunny | 19° /10° | 0 mm | 5 | |
| 20 Sept. | Sunny | 20° /13° | 0 mm | 5 | |
| 21 Sept. |  Mist | 19° /12° | 0.5 mm | 4 | |
| 22 Sept. | Light rain shower | 14° /8° | 7.7 mm | 3 | |
| 23 Sept. | Patchy rain possible | 15° /7° | 1.8 mm | 4 | |
| 24 Sept. | Patchy rain possible | 16° /10° | 1.3 mm | 5 | |
| 25 Sept. | Partly cloudy | 15° /6° | 5.1 mm | 4 | |
| 26 Sept. | Light rain shower | 13° /7° | 9.7 mm | 3 | |
| 27 Sept. | Light rain shower | 13° /6° | 14.7 mm | 3 | |
| 28 Sept. | Light rain shower | 14° /6° | 1.6 mm | 3 | |
| 29 Sept. | Patchy rain possible | 14° /7° | 0.8 mm | 3 | |
| 30 Sept. | Light rain shower | 14° /8° | 9.4 mm | 3 | |
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Important Notice
Our weather forecast for Belfast 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 Belfast forecast closer to your planned date for the most up-to-date weather information.
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Belfast in September - FAQ
What are the expected maximum and minimum temperatures in Belfast during September?
During September, expect a variety of temperatures with highs around 15° and lows near 8°, suitable for diverse activities and preferences.
How much rainfall should be expected in Belfast during September?
Significant rainfall exceeding 109.1 mm is expected in Belfast during September, occurring over more than 22 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Belfast during September?
The average wind speed in Belfast during September is 23 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Belfast
Explore the daily rainfall trends and prepare for Belfasts September weather 💧
Typically, Belfast has 22 rainy days in September with a total of 109.1 mm of rainfall.
UV exposure in Belfast during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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