May weather forecast
Belfast, United Kingdom

The Northern Ireland City Hall located in Belfast, United Kingdom
The Northern Ireland City Hall located in Belfast, United Kingdom

Weather in May

May, the last month of the spring in Belfast, is a moderate month, with temperature in the range of an average high of 13.3°C (55.9°F) and an average low of 7.1°C (44.8°F).

Temperature

In Belfast, the average high-temperature in May is relatively the same as in April - a mild 13.3°C (55.9°F). In Belfast, the average low-temperature is 7.1°C (44.8°F).

Humidity

The months with the lowest humidity in Belfast are April and May, with an average relative humidity of 83%.

Rainfall

May is the month with the least rainfall in Belfast. 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, United Kingdom, is 10°C (50°F).
Note: At temperatures below 10°C (50°F), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 13°C (55.4°F) is not comfortable.

Daylight

The average length of the day in May is 16h and 7min.
On the first day of the month, sunrise is at 5:45 am and sunset at 8:56 pm. On the last day of May, sunrise is at 4:55 am and sunset at 9:47 pm BST.

Sunshine

The average sunshine in May in Belfast, United Kingdom, 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 health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: In May, the average maximum UV index of 4 translate into the following recommendations:
Take precautions - Protection against skin and eye damage is obliged. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
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FAQ

What is the temperature in May in Belfast?

The average high-temperature, in May, in Belfast, United Kingdom, is 13.3°C (55.9°F), while the average low-temperature is 7.1°C (44.8°F).

What are the least humid months in Belfast?

The months with the lowest humidity in Belfast are April and May, with an average relative humidity of 83%.

What is the average humidity in May in Belfast?

In Belfast, United Kingdom, the average relative humidity in May is 83%.

What is the driest month in Belfast?

May is the month with the least rainfall in Belfast. Rain falls for 17.8 days and accumulates 38mm (1.5") of precipitation.

How many days does it rain in May in Belfast?

In Belfast, in May, during 17.8 rainfall days, 38mm (1.5") of precipitation is typically accumulated.

When it does not snow in Belfast?

In Belfast, snow does not fall in April through October.

What is the sea water temperature in May in Belfast?

In May, the average sea temperature is 10°C (50°F). Swimming in 10°C (50°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation.

What is the average length of the day in May in Belfast?

The average day length in May is 16h and 7min.

What time are sunrise and sunset in May in Belfast?

In May, on the first day of the month, sunrise is at 5:45 am and sunset at 8:56 pm. On the last day of the month, in Belfast, United Kingdom, sunrise is at 4:55 am and sunset at 9:47 pm BST.

How long on average sun shines in May in Belfast?

In Belfast, United Kingdom, the average sunshine duration in May is 6.7h.

What is the month with the highest UV index in Belfast?

May through August, with an average maximum UV index of 4, are months with the highest UV index in Belfast, United Kingdom.

How high is the UV index in May in Belfast?

The average daily maximum UV index in May is 4. A UV Index estimate of 3 to 5 represents a medium health risk from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in May
Belfast, United Kingdom

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).

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Average pressure in May
Belfast, United Kingdom

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).

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Average wind speed in May
Belfast, United Kingdom

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).

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Average humidity in May
Belfast, United Kingdom

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%).

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Average rainfall in May
Belfast, United Kingdom

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).

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Average rainfall days in May
Belfast, United Kingdom

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).

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Average snowfall in May
Belfast, United Kingdom

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).

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Average snowfall days in May
Belfast, United Kingdom

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).

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Average sea temperature in May
Belfast, United Kingdom

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).

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Average daylight in May /
Average sunshine in May
Belfast, United Kingdom

Average daylight in May / Average sunshine in May - Belfast, United Kingdom
  • Average daylight in May: 16h and 7min

The month with the longest days is June (Average daylight: 17h and 11min).
The month with the shortest days is December (Average daylight: 7h and 22min).

  • 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).

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Average sunshine days in May
Belfast, United Kingdom

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).

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Average UV index in May
Belfast, United Kingdom

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).

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Average cloud cover in May
Belfast, United Kingdom

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).

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Average visibility in May
Belfast, United Kingdom

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).

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