Belfast
September
Weather in Belfast for September 2025
Your guide to Belfast weather in September - trends and predictions
In general, the average temperature in Belfast at the beginning of September is 18.6 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 13.3 °C by the end of September.
Expect significant rainfall in Belfast during September, with an average of 19 rainy days.
- New! Chat with our AI weatherman - it’s amazing and free.
11
Dry days
19
Rainy days
0
Snow days
16°/10°
Temperatures
24 km/h
Avg max wind
87 %
Avg humidity
Belfast in September average weather
Move between months or click on a day
| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  16° | 2 18° | 3  18° | 4 17° | 5  19° | 6 21° | 7 21° |
| 8 21° | 9 19° | 10  17° | 11 14° | 12 14° | 13  14° | 14 16° |
| 15  13° | 16  16° | 17  17° | 18 15° | 19 17° | 20 17° | 21 15° |
| 22 15° | 23 14° | 24 15° | 25 13° | 26 12° | 27 13° | 28 14° |
| 29 14° | 30 12° |
You can click on date
Access Belfast weather forecasts with a simple click. Select any date for comprehensive insights on temperature, rainfall, and wind conditions.
Temperatures trend during September in Belfast
See the weather trend as well as the moving average line
September weather day by day
Click on a date for more information
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| 1 Sept. | Patchy rain possible | 16° /11° | 0.7 mm | 4 | |
| 2 Sept. | Patchy rain possible | 18° /10° | 4.7 mm | 4 | |
| 3 Sept. | Sunny | 18° /9° | 0.3 mm | 5 | |
| 4 Sept. | Sunny | 17° /9° | 0.9 mm | 5 | |
| 5 Sept. | Partly cloudy | 19° /10° | 0 mm | 5 | |
| 6 Sept. | Partly cloudy | 21° /12° | 0 mm | 6 | |
| 7 Sept. | Patchy rain possible | 21° /12° | 1.2 mm | 5 | |
| 8 Sept. | Partly cloudy | 21° /11° | 0.9 mm | 5 | |
| 9 Sept. | Patchy rain possible | 19° /11° | 0.7 mm | 5 | |
| 10 Sept. | Moderate or heavy rain shower | 17° /10° | 8.1 mm | 4 | |
| 11 Sept. | Light rain shower | 14° /8° | 4.1 mm | 4 | |
| 12 Sept. | Partly cloudy | 14° /5° | 0.6 mm | 4 | |
| 13 Sept. | Overcast | 14° /5° | 0.6 mm | 4 | |
| 14 Sept. | Overcast | 16° /9° | 0.2 mm | 4 | |
| 15 Sept. | Moderate rain | 13° /8° | 9.2 mm | 4 | |
| 16 Sept. | Cloudy | 16° /7° | 0 mm | 4 | |
| 17 Sept. | Light rain | 17° /10° | 8.4 mm | 4 | |
| 18 Sept. | Patchy rain possible | 15° /9° | 2.2 mm | 4 | |
| 19 Sept. | Light rain | 17° /9° | 4.1 mm | 4 | |
| 20 Sept. | Light rain shower | 17° /9° | 2.3 mm | 4 | |
| 21 Sept. | Light rain shower | 15° /7° | 0.7 mm | 4 | |
| 22 Sept. | Light rain shower | 15° /8° | 1.6 mm | 4 | |
| 23 Sept. | Light drizzle | 14° /6° | 0.6 mm | 4 | |
| 24 Sept. | Light rain shower | 15° /10° | 7.4 mm | 4 | |
| 25 Sept. | Patchy rain possible | 13° /9° | 1.9 mm | 4 | |
| 26 Sept. | Light rain shower | 12° /7° | 14.5 mm | 3 | |
| 27 Sept. | Light rain shower | 13° /6° | 10.6 mm | 3 | |
| 28 Sept. | Light rain shower | 14° /6° | 2.1 mm | 4 | |
| 29 Sept. | Patchy rain possible | 14° /7° | 1 mm | 4 | |
| 30 Sept. | Light rain shower | 12° /8° | 12.2 mm | 3 | |
| Next | |||||
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.
Belfast in September - FAQ
What are the expected maximum and minimum temperatures in Belfast during September?
Enjoy moderate daytime temperatures of up to 16° and cooler nights around 10°. 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 128.1 mm is expected in Belfast during September, occurring over more than 19 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 24 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 💧
UV exposure in Belfast during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
Quick links
You are here
Where is Belfast?Get accurate weather forecasts for Belfast, located at latitude 54.597 and longitude -5.925. Stay updated with localized weather information tailored for Belfast.
Related locations
Select a location for accurate weather forecast
More Locations Found a mistake?
We appreciate your attention to details. Tell us here.