As with the vast majority of the rest of Ireland, Belfast has a temperate oceanic climate , with a narrow range of temperatures and rainfall throughout the year. The climate of Belfast is significantly milder than most other locations in the world at a similar latitude, due to the warming influence of the Gulf Stream. There are currently five weather observing stations in the Belfast area: Helen’s Bay, Stormont, Newforge, Castlereagh, and Ravenhill Road. Slightly further afield is Aldergrove Airport. The highest temperature recorded at any official weather station in the Belfast area was 30.8 °C (87.4 °F) at Shaw’s Bridge on 12 July 1983.
The city gets significant precipitation (greater than 1mm) on 157 days in an average year with an average annual rainfall of 846 millimetres (33.3 in), less than areas of northern England or most of Scotland, but higher than Dublin or the south-east coast of Ireland. As an urban and coastal area, Belfast typically gets snow on fewer than 10 days per year. The absolute maximum temperature at the weather station at Stormont is 29.7 °C (85.5 °F), set during July 1983. In an average year the warmest day will rise to a temperature of 25.0 °C (77.0 °F) with a day of 25.1 °C (77.2 °F) or above occurring roughly once every two in three years. The absolute minimum temperature at Stormont is −9.9 °C (14 °F), during January 1982, although in an average year the coldest night will fall no lower than −4.5 °C (23.9 °F) with air frost being recorded on just 26 nights. The lowest temperature to occur in recent years was −8.8 °C (16.2 °F) on 22 December 2010.
The nearest weather station for which sunshine data and longer term observations are available is Belfast International Airport (Aldergrove). Temperature extremes here have slightly more variability due to the more inland location. The average warmest day at Aldergrove for example will reach a temperature of 25.4 °C (77.7 °F), (1.0 °C [1.8 °F] higher than Stormont) and 2.1 days should attain a temperature of 25.1 °C (77.2 °F) or above in total. Conversely the coldest night of the year averages −6.9 °C (19.6 °F) (or 1.9 °C [3.4 °F] lower than Stormont) and 39 nights should register an air frost. Some 13 more frosty nights than Stormont. The minimum temperature at Aldergrove was −14.9 °C (5.2 °F), during December 2010.