Belfast climate
Belfast (Northern Ireland, United Kingdom) has a temperate oceanic climate (Köppen Cfb). The average temperature over the year is 10 °C50 °F, and about 1,068 mm42 in of precipitation falls in an average year.
Temperature by month
Precipitation by month
Belfast climate table
| Month | High °C°F | Low °C°F | Mean °C°F | Precip. mmin |
|---|---|---|---|---|
| Jan | 846 | 540 | 643 | 983.9 |
| Feb | 745 | 440 | 642 | 783.1 |
| Mar | 847 | 540 | 644 | 763.0 |
| Apr | 1151 | 643 | 847 | 602.4 |
| May | 1356 | 847 | 1151 | 712.8 |
| Jun | 1660 | 1152 | 1356 | 833.3 |
| Jul | 1763 | 1254 | 1559 | 903.5 |
| Aug | 1763 | 1355 | 1559 | 993.9 |
| Sep | 1660 | 1153 | 1456 | 823.2 |
| Oct | 1356 | 1049 | 1152 | 1164.6 |
| Nov | 1050 | 745 | 948 | 1124.4 |
| Dec | 847 | 542 | 744 | 1044.1 |
| Year | 1763 | 440 | 1050 | 1,06842 |
“Year” row: highest monthly high, lowest monthly low, annual mean and annual total.
| Month | Humid. | Cloud | Solar | Daylight |
|---|---|---|---|---|
| Jan | 91% | 81% | 0.6 | 7:49 |
| Feb | 90% | 79% | 1.3 | 9:37 |
| Mar | 88% | 76% | 2.5 | 11:40 |
| Apr | 86% | 72% | 3.9 | 13:00 |
| May | 85% | 70% | 5.0 | 16:03 |
| Jun | 85% | 75% | 5.1 | 17:14 |
| Jul | 86% | 77% | 4.8 | 16:44 |
| Aug | 87% | 76% | 4.0 | 14:54 |
| Sep | 88% | 76% | 2.8 | 12:37 |
| Oct | 88% | 79% | 1.5 | 10:22 |
| Nov | 90% | 80% | 0.7 | 8:20 |
| Dec | 91% | 80% | 0.4 | 7:17 |
Humid. = average relative humidity at 2 m; cloud = average cloud amount; solar = average daily solar energy reaching the ground in kWh/m² (all-sky); daylight in hours:minutes, calculated for the 15th of each month.
What the climate of Belfast is like
The warmest month is August, with an average high of 17 °C63 °F and a low of 13 °C55 °F. The coldest is February, when highs average 7 °C45 °F and lows 4 °C40 °F. There is a clear seasonal cycle, with 9 °C16.3 °F between the average temperature of the warmest and the coolest month.
It is wet, with about 1,068 mm42 in of precipitation per year. Rain is spread fairly evenly through the year. The wettest month is October (116 mm4.6 in), the driest is April (60 mm2.4 in).
Relative humidity ranges from 85% in May to 91% in December. The clearest skies (lowest average cloud amount, 70%) are typical of May. Average wind speed near the ground ranges from 13 km/h (8 mph) in July to 22 km/h (13 mph) in January. Daylight lasts from about 7.3 hours in December to 17.2 hours in June.
Best time to visit Belfast
Based on these averages, the most comfortable months for sightseeing and outdoor activities are June–September: average highs of 16 °C60 °F to 17 °C63 °F with 82 mm3.2 in to 99 mm3.9 in of precipitation per month.
The most challenging month is January, which is cold, with average highs of 8 °C46 °F.
Comfort score: months are ranked by how close they come to an average high of 21–28 °C (70–82 °F), lows above 5 °C (41 °F), little precipitation and moderate humidity. The best-ranked months of each place are recommended, even where none meets all of these. These are general rules of thumb applied to long-term averages.
What to pack for Belfast
- Winter (December–February) — highs 745 to 8 °C47 °F, lows 440 to 5 °C42 °F, about 93 mm3.7 in of precipitation a month. Pack a warm coat, layers and closed shoes and an umbrella or light rain jacket.
- Spring (March–May) — highs 847 to 13 °C56 °F, lows 540 to 8 °C47 °F, about 69 mm2.7 in of precipitation a month. Pack a warm coat, layers and closed shoes.
- Summer (June–August) — highs 1660 to 17 °C63 °F, lows 1152 to 13 °C55 °F, about 91 mm3.6 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket and an umbrella or light rain jacket.
- Autumn (September–November) — highs 1050 to 16 °C60 °F, lows 745 to 11 °C53 °F, about 103 mm4.1 in of precipitation a month. Pack long sleeves, a sweater and a medium jacket and an umbrella or light rain jacket.
How Belfast compares
Compared with Dublin, about 142 km to the south, Belfast has practically the same average temperature and receives 9% more precipitation (1,068 mm42 in vs 983 mm39 in). The difference is largest in July (0.5 °C0.9 °F cooler).
Of the 66 places in the United Kingdom covered by World Climates, Belfast is the 35th warmest by annual mean temperature and the 10th wettest by annual precipitation. See all of them on the United Kingdom climate page.
Places in other countries with the most similar temperature and rainfall pattern: Dublin (Ireland, Cfb), Limerick (Ireland, Cfb) and Cork (Ireland, Cfb).
Nearby places
- Isle of Man (Douglas) 106 km · 11 °C51 °F · 1,124 mm44 in
- Dublin 142 km · 10 °C50 °F · 983 mm39 in
- Valley 171 km · 11 °C52 °F · 1,123 mm44 in
- Glasgow 176 km · 9 °C48 °F · 1,380 mm54 in
- Blackpool 206 km · 10 °C50 °F · 1,164 mm46 in
- Preston 229 km · 10 °C49 °F · 1,147 mm45 in
- Edinburgh 229 km · 9 °C48 °F · 889 mm35 in
- Birkenhead 233 km · 10 °C50 °F · 980 mm39 in
Frequently asked questions
What is the warmest month in Belfast?
August is the warmest month in Belfast, with an average high of 17 °C (63 °F) and an average low of 13 °C (55 °F).
What is the coldest month in Belfast?
February is the coldest month, with an average high of 7 °C (45 °F) and an average low of 4 °C (40 °F).
When does it rain the most in Belfast?
October is the wettest month with about 116 mm (4.6 in) of precipitation; April is the driest with about 60 mm (2.4 in).
What is the best time to visit Belfast?
Judging by long-term averages, the most comfortable months are June–September.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.