Belfast
September
Weather in Belfast for September 2026
Your guide to Belfast weather in September - trends and predictions
In general, the average temperature in Belfast at the beginning of September is 17.9 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 13.9 °C by the end of September.
The climate of Belfast in September is notably wet, with an average of 14 rainy days, and a total of 235.5 mm of precipitation.
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Temperatures
Rain 🌧️
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16
Dry days
14
Rainy days
0
Snow days
18°/7°
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 | 16° /10° | 1.2 mm | 4 | |
| 2 Sept. | Light rain shower | 18° /9° | 3.7 mm | 4 | |
| 3 Sept. | Light rain shower | 16° /9° | 6 mm | 4 | |
| 4 Sept. |  Sunny | 17° /8° | 1.9 mm | 4 | |
| 5 Sept. |  Partly cloudy | 18° /9° | 0 mm | 5 | |
| 6 Sept. | Partly cloudy | 20° /11° | 0 mm | 5 | |
| 7 Sept. | Patchy rain possible | 20° /11° | 2.7 mm | 4 | |
| 8 Sept. | Partly cloudy | 19° /9° | 0.8 mm | 5 | |
| 9 Sept. | Patchy rain possible | 18° /10° | 0.8 mm | 4 | |
| 10 Sept. |  Moderate or heavy rain shower | 17° /10° | 8.2 mm | 4 | |
| 11 Sept. | Light rain shower | 14° /8° | 3.4 mm | 3 | |
| 12 Sept. | Light rain shower | 14° /6° | 1.2 mm | 4 | |
| 13 Sept. |  Overcast | 14° /5° | 1.5 mm | 3 | |
| 14 Sept. | Overcast | 16° /8° | 3.3 mm | 4 | |
| 15 Sept. |  Moderate rain | 14° /9° | 8.6 mm | 3 | |
| 16 Sept. |  Cloudy | 16° /7° | 0.1 mm | 4 | |
| 17 Sept. |  Light rain | 17° /10° | 10.8 mm | 4 | |
| 18 Sept. | Patchy rain possible | 16° /9° | 3.8 mm | 4 | |
| 19 Sept. | Light rain | 16° /9° | 4.7 mm | 4 | |
| 20 Sept. | Light rain shower | 16° /8° | 1.7 mm | 4 | |
| 21 Sept. | Light rain shower | 14° /6° | 0.7 mm | 4 | |
| 22 Sept. | Light rain shower | 14° /6° | 1 mm | 4 | |
| 23 Sept. | Light drizzle | 14° /5° | 0.4 mm | 4 | |
| 24 Sept. | Light rain shower | 15° /8° | 4.9 mm | 4 | |
| 25 Sept. | Patchy rain possible | 14° /8° | 1.3 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?
Enjoy moderate daytime temperatures of up to 18° and cooler nights around 7°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Belfast during September?
Significant rainfall exceeding 235.5 mm is expected in Belfast during September, occurring over more than 14 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 💧
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