Normal weather for Northern Ireland in September
It's cool to moderate in September in Northern Ireland with an average temperature of 17°C. Temperatures this month range from a low of 15°C to a high of 19°C. At night, you can expect temperatures between 9°C and 13°C.
In September, there is an average of 71 mm of precipitation, spread over 9 days. The wind speed is around 4 Bft, mostly coming from the South.
Northern Ireland in September |
London | ||
|---|---|---|---|
 Average Temperature |
17°C | 20°C | |
 High Temp |
19°C | 22°C | |
| Low Temp |
15°C | 17°C | |
 Total Precipitation |
71 mm | 44 mm | |
| Rainy Days |
9 days | 8 days | |
Start of September
The month of September starts in Northern Ireland with mild temperatures, averaging around 18°C during the day and nights close to 13°C. A few showers might pop up in the first days of the month, but the weather remains mostly sunny and dry.
Since temperatures can differ between day and night, it’s a good idea to dress in layers. During the day, a shirt, maybe a light cardigan, and light trousers will do. In the evening and morning, we recommend a light coat, jumper or cardigan, and long trousers.
Mid-September
By mid-September, the average daytime temperature drops to around 17°C, with nights close to 11°C. There might be a few showers during this period, but plenty of dry days with sunshine too.
Temperatures vary between day and night, so it’s smart to wear layers. During the day, go for a light coat, jumper or cardigan, and long trousers. In the evening and morning, we recommend a warm coat, jumper or cardigan, and long trousers.
End of September
By the end of September, the average daytime temperature in Northern Ireland will be around 16°C, with nights close to 10°C. A shower might show up, but overall the weather will be dry and sunny.
As it gets cooler in the evening, it’s best to wear layers. During the day, go for a light coat, jumper or cardigan, and long trousers. In the evening and morning, we recommend a warm coat, jumper or cardigan, and long trousers.
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UV index
The UV index is a maximum of 5 this month. That's a moderate value on the intensity scale of 1 to 11. Unprotected skin can burn in about 30 minutes.
Is September a good time to visit Northern Ireland?
Looking for sun and warm weather? Then September isn’t the best time to be in Northern Ireland. The temperature is too low this month for a warm stay.
Temperature records for Northern Ireland in September
With 25°C, Northern Ireland hit the highest temperature in the last 10 years in September 2023. The lowest daytime temperature in this month was 10°C in 2018. The extreme night temperatures ranged from a low of 3°C to a high of 17°C.
Check out the climate of Northern Ireland for all months and discover the best travel time
You can check out all destinations in Northern Ireland for a full picture of the climate.
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Daily Temperature in September in Northern Ireland
This chart shows the average daily temperatures, both day and night, for each day in September in Northern Ireland, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Weather experiences in September in Northern Ireland
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Sometimes too cold for this time of year, the temperature wa... more
Daily Precipitation in September in Northern Ireland
The chart below shows the average daily precipitation in September for Northern Ireland, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for September, you can expect around 9 days of rain in Northern Ireland.
Daily UV Index in September in Northern Ireland
This chart shows the average daily UV index in September in Northern Ireland, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in September in Northern Ireland Over the Years
This chart shows the average temperature in September in Northern Ireland, measured in degrees Celsius, over the past years.
Total Precipitation in September in Northern Ireland Over the Years
This chart shows the average precipitation in September in Northern Ireland, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Daily climate in September for Northern Ireland
Click on a specific day in September for detailed info on the typical weather on that day in Northern Ireland. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in Northern Ireland
The weather in September in Northern Ireland is rated 3 out of 5 stars by 1 visitor. Have you been to Northern Ireland? Share your weather experience to help other visitors.
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Sometimes too cold for this time of year, the temperature was usually around 15 degrees. There was occasional rain and clouds, but there were also moments of beautiful sunshine. An umbrella is a must!— This text is automatically translated to English
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Average Weather in Northern Ireland by Month
Click on a month below to see detailed weather info for Northern Ireland. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
Or check out the climate of Northern Ireland for all months at once
