Belfast, the capital of Northern Ireland, features a temperate oceanic climate with cool, damp winters and mild, relatively rainy summers. The city experiences moderate temperatures year-round, frequent clouds, and regular rainfall, making it a lush and green destination with distinct seasonal changes and comfortable conditions for sightseeing and outdoor activities.
The best times to travel section shows how the months compare for a visit, so you can find the time of year that fits what you want to do.
Background colours of the months:
The colour shows the typical temperature: yellow (hot), green (mild) and blue (cold). How strong the colour is shows the travel season: full colour means high season, soft colour means shoulder season and soft-striped means off season.
Weather symbols:
Each month has one symbol showing what the weather is typically like, such as hot and sunny, freezing or a rainy or snowy season. Use them to quickly spot months that match the weather you want, or to avoid the ones that don't.
Crowdedness:
The people icon shows how busy the place usually is. The more people, the more crowded it gets.
Additional notes:
The grey info boxes point out special things worth knowing, like recurring weather issues or seasonal events.
Belfast’s climate is shaped by its coastal location and Atlantic influences, resulting in mild winters and cool summers. Winters (December–February) are cold and wet, with average highs of 7–8°C and lows near 2°C. Frost and occasional snow are possible, but snow rarely accumulates for long. Rain is frequent, especially from October to January, with December being one of the wettest months (up to 105 mm). Winter days are short, with just 1–2 hours of sunshine and about 8 hours of daylight. Winds are often brisk, adding to the chill, and humidity is high year-round.
Summers (June–August) are mild and comfortable, with average highs of 17–19°C and lows around 11–12°C. July is the warmest and sunniest month, offering up to 7–8 hours of sunshine daily and long daylight hours (up to 17 hours in June). Rainfall is moderate but occurs throughout the summer, so an umbrella is always useful. Spring (March–May) and autumn (September–November) are transitional, with spring bringing gradual warming and blooming gardens (highs of 10–15°C), and autumn offering colourful foliage and cooling temperatures. Annual precipitation is about 850 mm, with rain possible in any month, and the city enjoys 1,300–1,900 hours of sunshine per year. Winds are generally moderate to strong, especially in autumn and winter.
| Average climate data for Belfast, United Kingdom | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Average maximum temperature (°C) | 7 | 7 | 8 | 11 | 13 | 16 | 17 | 17 | 15 | 13 | 9 | 7 | 17 |
| Average minimum temperature (°C) | 3 | 3 | 3 | 5 | 7 | 10 | 11 | 11 | 10 | 8 | 6 | 4 | 3 |
| Average precipitation (mm) | 45 | 52 | 48 | 39 | 38 | 64 | 60 | 73 | 40 | 50 | 66 | 51 | 626 |
| Average rainfall days (days) | 18 | 16 | 18 | 16 | 18 | 20 | 22 | 23 | 16 | 18 | 19 | 16 | 220 |
| Average snowfall (mm) | 10 | 25 | 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 2 | 6 | 47 |
| Average snowfall days (days) | 3 | 3 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 8 |
| Average relative humidity (%) | 88 | 87 | 84 | 83 | 83 | 84 | 88 | 86 | 87 | 88 | 88 | 88 | 86 |
| Average wind speed (km/h) | 21 | 21 | 18 | 17 | 16 | 14 | 14 | 15 | 17 | 18 | 20 | 21 | 18 |
| Average water temperature (°C) | 9 | 8 | 8 | 9 | 10 | 12 | 14 | 14 | 14 | 13 | 12 | 11 | 11 |
| Average daily daylight hours (h) | 8 | 9 | 11 | 14 | 16 | 17 | 16 | 14 | 12 | 10 | 8 | 7 | 12 |
| Average daily sunshine hours (h) | 3 | 3 | 4 | 6 | 6 | 7 | 6 | 6 | 6 | 3 | 3 | 4 | 5 |
| Average cloud coverage (%) | 62 | 62 | 61 | 56 | 56 | 60 | 60 | 59 | 59 | 60 | 60 | 58 | 59 |
| Average UV index | 2 | 2 | 2 | 3 | 4 | 4 | 4 | 4 | 3 | 3 | 2 | 2 | 3 |
The best time to visit Belfast is from June to August, when temperatures are mild (17–19°C), days are long and relatively sunny, and the city’s parks and gardens are at their most vibrant. This period is ideal for sightseeing, festivals, and outdoor activities, though rain showers remain likely, so pack an umbrella.
The least favourable time to visit Belfast is from November to February, when days are short, temperatures are cool (7–8°C), and rain, wind, and clouds are frequent. While snow is rare, dampness and limited sunshine can make the city feel colder and less inviting for outdoor pursuits.
Belfast’s annual average temperature is about 9–10°C. January and February are the coldest months (highs 7–8°C, lows 2°C), while July is the warmest (highs 18–19°C, lows 11–12°C).
Belfast receives about 850 mm of rain annually, with precipitation spread year-round. December and January are wettest. Snow is rare, but frost and occasional snowfalls can occur in winter.
Belfast enjoys about 1,300–1,900 hours of sunshine per year. July is the sunniest month (up to 7–8 hours/day), while December and January are the least sunny (1–2 hours/day).
Late spring (May–June) and summer (July–August) are best for outdoor activities, with mild temperatures, long days, and more sunshine. Summer is ideal for festivals, walking, and exploring the city’s parks.
Belfast itself is not a winter sports destination. Snow is rare and temperatures are too mild for reliable ice or snow-based activities. For winter sports, head to the Mourne Mountains or Scotland.
Swimming outdoors is most comfortable in August and September, when sea temperatures reach 14°C. Even then, the water is cool for most swimmers, but beach activities are popular on warm, calm days.
Pack layers for spring and autumn, light clothing and rain gear for summer, and insulated, waterproof clothing for winter. An umbrella and windproof jacket are useful year-round.
The warmest month, with the highest average maximum temperature, is July (16.9 °C). The month with the lowest average maximum temperature is January (6.7 °C). Overall, the average maximum temperature over the whole year is 11.6 °C.
The month with the highest average minimum temperature is August (11.2 °C). The coldest month, with the lowest average minimum temperature, is February (2.7 °C). Overall, the average minimum temperature over the whole year is 6.7 °C.
The month with the highest average water temperature is September (14.3 °C). The month with the lowest average water temperature is March (8 °C). Overall, the average water temperature over the whole year is 11.1 °C.
The wettest month, with the highest amount of precipitation, is August (72.7 mm). The driest month, with the least amount of precipitation, is May (37.6 mm). Over the whole year there are 625.9 mm of rainfall on average.
The month with the most days of rain is August (23 days). The month with the fewest days of rain is April (16.2 days). Over the whole year there are 220.1 days of rain on average.
The month with the most snowfall is February (25.2 mm). The months with the least snowfall are April, May, June, July, August, September and October (0 mm). Over the whole year there are 47.3 mm of snowfall on average.
The month with the most days of snowfall is February (2.8 days). The months with the fewest days of snowfall are June, July and September (0 days). Over the whole year there are 8.5 days of snowfall on average.
The month with the highest average relative humidity is December (87.9 %). The month with the lowest average relative humidity is May (82.8 %). The overall average relative humidity over the whole year is 86.1 %.
The windiest month, with the highest average wind speed, is January (21.5 km/h). The calmest month, with the lowest average wind speed, is June (13.6 km/h). The overall average wind speed over the whole year is 17.6 km/h.
The month with the cloudiest skies, so the highest cloud coverage, is February (62.5 %). The month with the clearest skies, so the lowest cloud coverage, is April (55.9 %). Over the whole year there is an average cloud coverage of 59.4 %.
The month with the longest days, so the most daylight, is June (Average daylight: 17 h). The month with the shortest days, so the least daylight, is December (Average daylight: 7 h). Over the whole year there are 11.9 h of daylight per day on average.
The month with the most sunshine per day is June (Average sunshine: 7 h). The month with the least sunshine per day is November (Average sunshine: 3 h). Over the whole year there are 4.8 h of sunlight per day on average.
The months with the highest average UV index are May, June, July and August (UV index: 4). The months with the lowest average UV index are January, February, March, November and December (UV index: 2). Over the whole year the average UV index is 2.9.
