Derry Weather in September
Thinking of visiting Derry in September? Expect moderate temperatures reaching 17°C (63°F) during the day, dropping to 10°C (50°F) at night, and note that quite a bit of rainfall is likely.
Rainfall in Derry in September
You can expect rain on around 21 days based on historical patterns, with 88 mm (3.5 in) average for the month. Rain falls on many days this month, but usually in relatively small amounts. A light waterproof is more useful than a heavy umbrella.
Temperature in Derry in September
In September, Derry sees moderate temperatures, with highs of 17°C (63°F). Nights drop to around 10°C (50°F). A light jacket or extra layer can be useful, especially outside the warmest hours of the day. At 10°C (50°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping.
Sunshine in Derry in September
The month experiences a moderate amount of sunlight, with 118 hours of sunshine. This provides a nice balance between sunshine and clouds.If you're inclined towards comfortable temperatures and drier conditions, September is a good time to visit Derry.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Ireland, check out our Derry's climate page.
Derry Temperature in September
Min Temperature
10°C (50°F)
Max Temperature
17°C (63°F)
Chance of Rain
70%
Precipitation
88 mm (3.5 in)
Rainy days
21 days
Sunshine
118 hours
Percentage Sunshine
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Derry typically stay consistent throughout September, with daily highs averaging around 17°C (63°F). Nights are cool, with lows typically ranging from 9°C (48°F) to 11°C (52°F).
Average temperatures in September
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in September
Historical weather for Derry in September
Browse day-by-day weather records for Derry spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Derry historical weather extremes in September
Our historical data for Derry spans 1976 to 2025, revealing these weather extremes.
- On September 7, 2023, temperatures climbed to 27°C (81°F), marking the warmest September day on record.
- The coldest September day was on September 24, 2012, with a maximum of 10°C (50°F).
- The lowest overnight temperature recorded in September was 1°C (34°F) (September 22, 2025).
- Peak precipitation in September occurred on September 6, 2010, when 41 mm (1.6 in) of precipitation was measured.
Best Places in Ireland in September
Find out more about the weather in Ireland and which places have the best travel conditions in this month. See all of Ireland in September →
perfect weather
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tolerable
unpleasant
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What to Wear in Derry in September
Comfortable temperatures call for an easy wardrobe in September. Pack summer basics like t-shirts and shorts, but include a light jacket for cooler moments. A pair of comfortable walking shoes is essential. Expect heavy rainfall, so bring good rain protection and waterproof bags. Bring sunglasses since you'll have some sunny periods throughout the monthWhat To Do in Derry in September
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Ireland, check out our Derry's climate page.
See the full Derry climate overview or explore weather in Ireland.
