Weather in Belfast: Climate, Seasons, and Average Monthly Temperature

Belfast's Saint Anne's Cathedral - the enormous

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Belfast is the capital of Northern Ireland and the largest city in the country, falling behind Dublin to the second-largest city in all of Ireland. Like most of the east coast of Ireland, Belfast is generally cool but rarely cold, thanks to the Gulf Stream. Belfast is warmer than many other locations at a similar latitude, but it does still receive more rain than Dublin and other areas further to the south-east.

With 157 average days of rain per year, it is never a bad idea to be prepared for wet weather in Belfast. However, late spring to late summer (May-September) tends to be warmer and drier than other months of the year. November tends to be the rainiest in terms of the number of inches of water that falls (3.78 inches) but January has the highest number of rainy days (15).

Ready to plan your trip to Belfast? Here is what you need to know about the climate and weather to help you pick the best times and pack appropriately.

Fast Climate Facts

  • Hottest Month: July
  • Coldest Month: February
  • Wettest Month: November

Spring

The best thing about Spring in Belfast is the longer days that appear after the dark winter. Thanks to its northern climate, daylight is at a premium during the colder months in Belfast and in March the average rises to 12 hours a day, increasing to 14 hours of daylight in April and a fabulous 16 hours between sunrise and sunset in May. The average high spring temperatures in Belfast are in the 50s Fahrenheit, and the rain tends to decrease as the days grow longer and warmer.

What to pack: The spring climate in Belfast is temperate and usually mild but it is still good to be prepared for spots of wet weather when you pack for your trip. March can have up to 14 rainy days on average, so be sure to bring an umbrella and waterproof shoes. You don’t need cold-weather gear by April and May, but a light jacket weather jacket will help ensure you are still ready for the colder nights. In March, plan for it to still be chilly and opt for some more accessories like thick socks and a knit hat to stay protected from lingering winter elements.

Average Temperatures and Rainfall by Month

  • March: 50 F (10 C) / 38 F (3 C), 2.99 inches
  • April: 54 F (12 C) / 40 F (4 C), 2.65 inches
  • May: 59 F (15 C) / 44 F (7 C), 2.55 inches

Summer

The longest and warmest days arrive in Belfast between June and August. Expect 15-17 hours of sunlight per day, with the twilight stretching on long into the evening. The average temperatures also reach their peak during this time, while the rainfall tends to be some of the lowest of the year. It may not be beach weather every day, but you are most likely to find good weather in Belfast during this summer period.

What to pack: You don’t need a coat for summer in Belfast, but you may want to bring a few light layers just in case the temperature drops after the sun goes down. Rainfall is less in summer but still possible, so a collapsible umbrella is a good idea, particularly in August which is wetter than June and July. Shorts are probably not necessary, but light shirts and pants are all you need to enjoy the relatively warmer days in comfort. Nights can remain cool, so a cardigan will be put to good use.

Average Temperatures and Rainfall by Month

  • June: 64 F (18 C) / 50 F (10 C), 2.69 inches
  • July: 77 F (20 C) / 53 F (11 C), 2.61 inches
  • August: 66 F (19 C) / 52 F (11 C), 3.35 inches

Fall

September may still feel like the end of summer but autumn has truly arrived by October when the rain picks up and the (relatively) cooler weather arrives in Belfast. As fall settles in, the days grow shorter, with the average hours of daylight dropping from 12 in September to a mere eight in November. It rarely freezes in fall in Belfast, but the colder temperatures will be noticeable.

What to pack: The weather during fall in Belfast can change quickly. Even when days start out with a bit of sun, the rain can arrive by the afternoon, so it is best to be prepared with a light waterproof jacket and shoes. Heavy-duty boots are rarely necessary, but warm layers will help ensure that you stay cozy and dry, and can shed a sweater if the day warms up.

Average Temperatures and Rainfall by Month

  • September: 47 F (8 C) / 37 F (3 C), 3.56 inches
  • October: 47 F (8 C) / 37 F (3 C), 3.56 inches
  • November: 47 F (8 C) / 37 F (3 C), 3.56 inches

Winter

Winter brings the coldest average temperatures to Belfast, as well as some of the highest rainfall. Snow is rare but not unheard of during winter, though Belfast can receive snow up to 10 days a year on average. You are more likely to encounter frost in the evenings and mornings than any true snowfall. One thing to keep in mind is the limited amount of daylight in Belfast during the winter. December and January tend to have the shortest days of the year, with an average of eight hours of daylight day.

In February, the average daylight starts to inch up to almost 10 hours per day.

What to pack: If you plan on exploring the city and the surrounding countryside during the winter months, pack warm, weather-resistant clothes. A thick coat, sturdy boots, and cold-weather accessories like hats, scarves, gloves, will ensure that you are ready for whatever the Northern Ireland winter decides to bring.

Average Temperatures and Rainfall by Month

  • December: 47 F (8 C) / 37 F (3 C), 3.56 inches
  • January: 46 F (8 C) / 36 F (2 C)
  • February: 47 F (8 C) / 36 F (2 C), 3.47 inches
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