May could be a good time to visit Belfast, as the weather is generally fine. The average high temperature is around +14°C, and there are typically 4 sunny days in May. However, expect about 19 rainy days, and total monthly rainfall of approximately 69 mm. The weather is changeable so pack for every eventuality. Search flightsin one click on Avionero.
Good to know:
May is usually the driest month of the year in Belfast
Average weather
☀️
+14°C
Avg. max. temperature
-1°C
Min.
+25°C
Max.
69 mm
Total precipitation
76%
Avg. humidity
4 m/s
Avg. wind
4 ☀️
Sunny Days
8 ⛅️
Cloudy
19 🌦
Rainy
Our opinion: Belfast has OK weather in May.
Average temperature in Belfast in May
Here are the expected maximum, average and minimum temperatures in Belfast for May based on the historical data.
Last Year
Historical Data
The expected average maximum temperature in May is +16°C with a maximum of +21°C and a minimum of +5°C.
The average maximum temperature goes up 38% by the end of the month, compared with the beginning of the month, from +14°C to +20°C.
Is Belfast warm or cold in May?
Belfast is typically mild in May.
Maximum temperatures go up compared to the previous month from +11°C to +14°C. The minimum temperature also goes up from +5°C to +8°C.
Pack a light jacket as it will be warm in the day and cool in the evenings.
Take a look at how May is compared to other months in Belfast:
Water temperature in Belfast in May
Water in Belfast in May is Cold. It varies from +9°C to +11°C, with an average of +10°C.This is almost similar to the air temperature, which averages +14°C.
In May, water temperatures are average relative to the rest of the year:
The warmest water temperatures in Belfast are reached in September, when the average sea temperature rises to +14°C. The coldest water temperatures are in March, with an average of +8°C.
Can you swim in Belfast in May?
We would not recommend swimming in Belfast in May, the water is very cold (+10°C on average). Consider swimming only if you are an experienced cold-water swimmer with proper gear.
🦭
Cold
Below +16°C
🏄♂️
Fresh
16°C - 21°C
🏊
Comfortable
21°C - 25°C
👙
Warm
25°C - 28°C
🔥
Very warm
+28°C and up
You will need a full-body wetsuit, cap, gloves, a warm change of clothes, and a hot drink ready for after your swim.
Climate in Belfast in May
Belfast weather looks like this, on average, in May and the surrounding months.
April
May
June
Avg. temperature
+11°C
+14°C
+17°C
Min. temperature
-3°C
-1°C
+2°C
Max. temperature
+22°C
+25°C
+30°C
Rainfall
60 mm
69 mm
73 mm
Wind
4 m/s
4 m/s
4 m/s
Avg. water temperature
+9°C
+10°C
+12°C
Humidity
77%
76%
77%
Air pressure
1013 HPa
1014 HPa
1014 HPa
Sunny days
3
4
2
Cloudy days
8
8
8
Rainy days
18
19
19
Snowy days
0
0
0
May weather is still as ok as in April.It’s getting warmer as May arrives. The average maximum temperature goes up from +11°C to +14°C during the day.Prepare for more rain. Average rainfall goes from 60 mm to 69 mm.It feels drier, as humidity decreases from 77% to 76%.The average wind speed doesn’t change much during May, staying around 4 m/s.The good news is there are likely to be more sunny days in May, from 3 to 4.
Wind speed in Belfast in May based on historical data.
Last Year
Historical Data
The average wind speed is 3 m/s getting up to 7 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in Belfast is gradually decreasing during May, going from 4 m/s to 2 m/s over the course of the month.
Rain
Amount of rainfall in mm during May in Belfast based on historical data.
Last Year
Historical Data
Total precipitation in May is about 41 mm, with a 32% chance of rain on a typical day. The maximum amount of rainfall per day is around 11 mm, which is considered light rain.May is a pretty wet month with over 10 rainy days, so don’t forget to pack an umbrella, raincoat, and a pair of galoshes.
Here’s how May is compared with other months in the amount of precipitation, total mm:
Belfast wettest month is October, where a typical day has a 61% chance of precipitation and 91 mm of rainfall per day. April, on the other hand, is the driest month with a mere 60% chance of precipitation and 60 mm of rainfall per day.
How was the weather last May in Belfast?
This is the weather in Belfast in May 2023:
1 May
☁️
+14°C
2 May
☁️
+13°C
3 May
☁️
+15°C
4 May
☁️
+13°C
5 May
🌧️
+16°C
6 May
☁️
+16°C
7 May
☀️
+18°C
8 May
🌧️
+20°C
9 May
☀️
+18°C
10 May
🌧️
+16°C
11 May
🌧️
+15°C
12 May
☁️
+16°C
13 May
☁️
+17°C
14 May
🌧️
+14°C
15 May
☀️
+15°C
16 May
☀️
+15°C
17 May
☁️
+18°C
18 May
☁️
+17°C
19 May
☁️
+16°C
20 May
🌧️
+16°C
21 May
☁️
+16°C
22 May
☀️
+16°C
23 May
☁️
+16°C
24 May
☁️
+15°C
25 May
☁️
+17°C
26 May
☁️
+18°C
27 May
☁️
+19°C
28 May
☁️
+15°C
29 May
☁️
+17°C
30 May
☀️
+21°C
31 May
☀️
+20°C
In May 2023 Belfast had 7 sunny days, 18 cloudy days, and 6 rainy days. The average maximum temperature was +16°C, with an absolute maximum of +21°C and a minimum of +13°C. The average humidity was 81%, with a maximum of 100% and a minimum of 57%. The average wind speed was 3 m/s, with a maximum of 9 m/s and a minimum of 0 m/s.
Are you planning a trip in May?
Climate Change over Years
This is how Belfast climate have been changing during last 43 years period.
The climate in Belfast in May has not changed much over the last 43 years.
The average temperature was the lowest in 1979 (+11°C) and the highest in 1995 (+14°C). The driest year was 2003 with only 711 mm of rainfall, and the wettest year was 2019 with 1255 mm.
FAQ
Frequently asked questions about the weather in Belfast in May:
Is May a good time to visit Belfast?
It’s always a good time to visit Belfast, but the weather is changeable in May, so plan a mix of indoor and outdoor activities and exploring, and pack for every eventuality.
Can you sunbathe in Belfast in May?
May has mild temperatures in Belfast. Not ideal for sunbathing, but still good for daytime outdoor activities, but plan for cool evenings. Pack a light jacket and shorts!
Can you swim in Belfast in May?
Swimming in Belfast in May is challenging and not recommended for inexperienced swimmers or without proper equipment and preparation.
Is Belfast rainy in May?
Belfast is often rainy in May. You may get a bit damp when outside, so pack an umbrella, and maybe even a raincoat.
Is it sunny in Belfast in May?
Usually, it’s not very sunny in Belfast in May, often it’s pretty cloudy. Pack for any eventuality; layering can help reduce the number of bulky items needed.
Other cities in United Kingdom
Check out the weather for other cities in United Kingdom.
For this page, we’ve looked at the typical weather in Belfast, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.