Belfast Weather in September
September in Belfast averages 30°C (86°F) during the day and 26°C (79°F) at night. Quite a bit of rainfall is typical this month, with around 164 mm (6.5 in) on average. An umbrella is a good idea.
Rainfall in Belfast in September
Typically, you can expect about 14 days of rain this month, with 164 mm (6.5 in) on average. Rainfall intensity is on the higher side this month. Expect more substantial showers rather than light, passing rain.
Temperature in Belfast in September
In September, Belfast gets high temperatures, with highs of 30°C (86°F). Nights cool to around 26°C (79°F). This gives the month a fairly typical daily rhythm, with warmer afternoons and more comfortable nights. With overnight lows of 26°C (79°F), nights stay very warm. Air conditioning makes a real difference if you're sensitive to heat. A cold shower before bed can also help you get to sleep more comfortably.
Sunshine in Belfast in September
The city usually sees around 228 hours of sunlight, indicating many sunny days , a great month for sightseeing.September in Belfast has its charm, but if you're looking for destinations with pleasant temperatures and sunny skies, our weather planner can help you explore other options in the world.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Jamaica, check out our Belfast's climate page.
Belfast Temperature in September
Min Temperature
26°C (79°F)
Max Temperature
30°C (86°F)
Chance of Rain
46%
Precipitation
164 mm (6.5 in)
Rainy days
14 days
Humidity
78% *
Sunshine
228 hours *
Percentage Sunshine
*
Daily Historical Temperatures
49-year average (1976-2025)
Based on our historical records, temperatures in Belfast typically stay consistent throughout September, with daily highs averaging around 30°C (86°F). Nights are warm, with lows around 26°C (79°F).
Average temperatures in September
Daily Historical Precipitation
49-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 Belfast in September
Browse day-by-day weather records for Belfast spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Belfast historical weather extremes in September
Based on 20 years of weather observations in Belfast between 2005 and 2025, these are the recorded extremes.
- On September 25, 2006, temperatures climbed to 35°C (95°F), marking the warmest September day on record.
- The coldest September day was on September 28, 2010, with a maximum of 26°C (79°F).
- Belfast registered its coldest September night on September 25, 2025, with temperatures dropping to 22°C (72°F).
Best Places in Jamaica in September
Find out more about the weather in Jamaica and which places have the best travel conditions in this month. See all of Jamaica in September →
perfect weather
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unpleasant
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What to Wear in Belfast in September
Warm weather calls for comfortable, breathable clothing in September. Cotton t-shirts, shorts, light dresses, and sandals are perfect. You might still want a light layer for evenings or air-conditioned places (for example buses). Also bring a poncho, it will rain a lot! Waterproof everything you can. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.What To Do in Belfast 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 Jamaica, check out our Belfast's climate page.
Temperature Rainfall Sunshine Humidity
See the full Belfast climate overview or explore weather in Jamaica.
