Belfast Weather in September
Average highs run from 19°C on September 1 to 15°C on September 30, and lows from 11°C to 10°C. Normal precipitation for the month is 75 mm over about 16 wet days.
September day by day
The normal high and low for each date, and the record, in °C.
- Normal low
- Normal high
- Record high
- Record low
September at a glance
- Average high
- 17°C
- Average low
- 10°C
- Precipitation
- 75 mm
- Record high
- 26°CSep 7, 2023
- Record low
- 1°CSep 28, 1974
- Daylight
- 13 h 45 min to 11 h 38 min
- Cloud cover
- 76%
- Humidity
- 88%
- Dew point
- 11°C
- Wind
- 19.1 km/h
Every day of the month
A wet day has at least 1 mm of precipitation in the reanalysis.
| Date | Normal high | Normal low | Record high | Record low | Chance wet |
|---|---|---|---|---|---|
| Sep 1 | 19°C | 11°C | 23°C 2013 | 6°C 1975 | 52% |
| Sep 2 | 18°C | 11°C | 22°C 1999 | 6°C 1965 | 52% |
| Sep 3 | 18°C | 12°C | 24°C 2004 | 6°C 1965 | 52% |
| Sep 4 | 18°C | 11°C | 24°C 1999 | 6°C 1963 | 53% |
| Sep 5 | 18°C | 11°C | 25°C 2023 | 6°C 1992 | 54% |
| Sep 6 | 18°C | 11°C | 23°C 2005 | 5°C 1985 | 56% |
| Sep 7 | 18°C | 11°C | 26°C 2023 | 4°C 1965 | 57% |
| Sep 8 | 18°C | 11°C | 25°C 2023 | 3°C 1972 | 57% |
| Sep 9 | 17°C | 10°C | 22°C 1964 | 4°C 1977 | 56% |
| Sep 10 | 17°C | 10°C | 21°C 2014 | 2°C 1972 | 56% |
| Sep 11 | 17°C | 10°C | 21°C 2007 | 3°C 1986 | 57% |
| Sep 12 | 17°C | 10°C | 22°C 1991 | 5°C 2024 | 56% |
| Sep 13 | 17°C | 9°C | 22°C 2003 | 5°C 1986 | 55% |
| Sep 14 | 17°C | 10°C | 24°C 2020 | 4°C 1986 | 55% |
| Sep 15 | 16°C | 10°C | 22°C 1982 | 4°C 1986 | 54% |
| Sep 16 | 17°C | 10°C | 22°C 2003 | 3°C 1986 | 54% |
| Sep 17 | 17°C | 9°C | 22°C 1998 | 3°C 1976 | 54% |
| Sep 18 | 17°C | 10°C | 22°C 2019 | 4°C 1976 | 53% |
| Sep 19 | 17°C | 10°C | 20°C 1998 | 4°C 1986 | 51% |
| Sep 20 | 17°C | 10°C | 21°C 2013 | 4°C 1984 | 50% |
| Sep 21 | 17°C | 10°C | 20°C 2021 | 3°C 1983 | 49% |
| Sep 22 | 16°C | 10°C | 20°C 1978 | 2°C 1979 | 49% |
| Sep 23 | 16°C | 9°C | 20°C 2007 | 5°C 2003 | 51% |
| Sep 24 | 16°C | 10°C | 21°C 2021 | 5°C 2018 | 53% |
| Sep 25 | 16°C | 9°C | 20°C 2021 | 5°C 1987 | 54% |
| Sep 26 | 16°C | 9°C | 20°C 1985 | 3°C 1990 | 54% |
| Sep 27 | 16°C | 9°C | 21°C 2016 | 4°C 1991 | 55% |
| Sep 28 | 16°C | 10°C | 21°C 1986 | 1°C 1974 | 56% |
| Sep 29 | 16°C | 10°C | 20°C 2002 | 2°C 1974 | 56% |
| Sep 30 | 15°C | 10°C | 19°C 1983 | 3°C 1991 | 57% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (GMT+1).
- September 1
- sunrise 6:31 AM, sunset 8:16 PM
- September 30
- sunrise 7:24 AM, sunset 7:02 PM
Other months
Sources
Records: NOAA GHCN-Daily, station UKE00105877, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-26. Sun and moon: computed with the NOAA solar equations and Meeus.