Average 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.
Start of September
The month of September starts in Northern Ireland with mild temps, averaging around 18°C during the day and nights around 13°C. A few showers might pop up early in the month, but overall, it’ll stay mostly sunny and dry.
Mid September
By mid-September, daytime temps drop to around 17°C, with nights around 11°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.
End of September
By the end of September, the average daytime temperature in Northern Ireland is around 16°C, while nighttime temps are about 10°C. A shower might pop up, but overall, the weather will be dry and sunny.
In September, there is an average of 71 mm of precipitation, spread over 15 days. The wind speed is around 4 Bft, mostly coming from the South.
Northern Ireland in September |
New York | ||
|---|---|---|---|
 Average temperature |
17°C | 27°C | |
 Max. temperature |
19°C | 31°C | |
| Min. temperature |
15°C | -5°C | |
 Total precipitation |
71 mm | 57 mm | |
| Rainy days |
15 days | 9 days | |
August
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? September isn’t a good month to be in Northern Ireland. The temperatures are too low for a warm stay this month.
Temperature records
With 25°C in 2023, Northern Ireland reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 10°C in 2018. The extreme nighttime temperatures ranged from a lowest recorded value of 3°C to a highest value 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 to get the full picture of the climate.
Daily Temperature in September in Northern Ireland
This chart shows the average daily high and low temperatures in September for Northern Ireland, in degrees Celsius. The red line represents the highs, and the blue line shows the lows. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, provide the average temperatures for 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 millimeters over the past few years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are listed 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 it rained more often. But remember, it’s just an average, and every day can be different. Based on historical weather data for September, you can expect about 15 days of precipitation 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 few years.
Total precipitation in September in Northern Ireland over the years
This chart shows the average precipitation in September in Northern Ireland, measured in millimeters over the past years. Precipitation is always measured as water, whether it’s snow or hail.
Daily weather in September for Northern Ireland
Click on any day in September to get detailed info about the usual 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
