May weather forecastBelfast, United Kingdom
May weather for Belfast, United Kingdom: An average minimum temperature of 7.1°C (44.8°F) marks the month of May in Belfast, United Kingdom. On the first day of May in Belfast, United Kingdom, sunrise is at 5:43 am and sunset at 8:58 pm.

May
Weather in May
There is a noticeable jump in temperature in Belfast during May, creating a comfortable environment. This month boasts an increase in daylight hours, nearing their annual peak, which adds vibrancy to the city. High relative humidity persists, contributing to the occasional misty mornings and noteworthy precipitation. Moreover, the absence of snowfall remains, further solidifying a fully-fledged spring. In conclusion, May offers a mellow spring climate with warm temperatures, extended sunlight, and consistent rainfall devoid of any snow.Temperature
May experiences an average high-temperature of a mild 13.3°C (55.9°F), barely different from April's 10.8°C (51.4°F). An average minimum temperature of 7.1°C (44.8°F) marks the month of May in Belfast, United Kingdom.Humidity
April and May, with an average relative humidity of 83%, are the least humid months in Belfast.Rainfall
May is the month with the least rainfall. Rain falls for 17.8 days and accumulates 38mm (1.5") of precipitation.Snowfall
April through October are months without snowfall.Sea temperature
In May, the average sea temperature in Belfast is 10°C (50°F).Note: To swim in 10°C (50°F) at less than 10°C (50°F), ensure you're well-protected. Without it, be prepared for a sudden jolt of cold and breathing issues. Remember, even 13°C (55.4°F) is not welcoming.
Daylight
In May, the average length of the day is 16h and 7min.On the first day of May in Belfast, United Kingdom, sunrise is at 5:43 am and sunset at 8:58 pm. On the last day of the month, sunrise is at 4:54 am and sunset at 9:48 pm BST.
Sunshine
In May, the average sunshine is 6.7h.UV index
May through August, with an average maximum UV index of 4, are months with the highest UV index. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for the average person.Note: The daily high UV index of 4 during May translates into the following recommendations:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Belfast, United Kingdom
- Average high temperature in May: 13.3°C
The warmest month (with the highest average high temperature) is July (16.9°C).
The month with the lowest average high temperature is January (6.8°C).
- Average low temperature in May: 7.1°C
The month with the highest average low temperature is August (11.3°C).
The coldest month (with the lowest average low temperature) is February (2.8°C).
Average pressure in May
Belfast, United Kingdom
- Average pressure in May: 1015.6mbar
The month with the highest atmospheric pressure is May (1015.6mbar).
The month with the lowest atmospheric pressure is November (1007.3mbar).
Average wind speed in May
Belfast, United Kingdom
- Average wind speed in May: 15.8km/h
The windiest month (with the highest average wind speed) is January (21.3km/h).
The calmest months (with the lowest average wind speed) are June and July (13.7km/h).
Average humidity in May
Belfast, United Kingdom
- Average humidity in May: 83%
The months with the highest relative humidity are January and December (88%).
The months with the lowest relative humidity are April and May (83%).
Average rainfall in May
Belfast, United Kingdom
- Average rainfall in May: 38mm
The wettest month (with the highest rainfall) is August (72mm).
The driest month (with the least rainfall) is May (38mm).
Average rainfall days in May
Belfast, United Kingdom
- Average rainfall days in May: 17.8 days
The month with the highest number of rainy days is August (23 days).
The month with the least rainy days is April (16.1 days).
Average snowfall in May
Belfast, United Kingdom
- Average snowfall in May: 0mm
The month with the highest snowfall is February (25mm).
The months with the least snowfall are April, May, June, July, August, September and October (0mm).
Average snowfall days in May
Belfast, United Kingdom
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is February (2.8 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average sea temperature in May
Belfast, United Kingdom
- Average sea temperature in May: 10°C
The best month for swimming (with the highest average sea temperature) is September (14.3°C).
The coldest month (with the lowest average sea temperature) is March (8°C).
Average daylight in May /
Average sunshine in May
Belfast, United Kingdom
- Average daylight in May: 16h and 6min
The month with the longest days is June (Average daylight: 17h and 12min).
The month with the shortest days is December (Average daylight: 7h and 24min).
- Average sunshine in May: 6h and 42min
The month with the most sunshine is June (Average sunshine: 7h and 18min).
The month with the least sunshine is February (Average sunshine: 3h and 30min).
Average sunshine days in May
Belfast, United Kingdom
- Average sunshine days in May: 10.7 days
The month with the most sunshine days is April (11.5 days).
The month with the least sunshine days is August (5.6 days).
Average UV index in May
Belfast, United Kingdom
- Average UV index in May: 4
The months with the highest UV index are May, June, July and August (UV index 4).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in May
Belfast, United Kingdom
- Average cloud cover in May: 56
The months with the most cloud cover are January and February (Cloud cover 63).
The month with the least cloud cover is April (Cloud cover 55).
Average visibility in May
Belfast, United Kingdom
- Average visibility in May: 9km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (9km).





