Belfast Weather in May
May in Belfast brings moderate temperatures around 15°C (59°F) during the day, dropping to 8°C (46°F) at night, with quite a bit of rainfall expected, averaging around 77 mm (3 in) for the month.
Rainfall in Belfast in May
Analyzing past climate data, one can expect approximately 16 days of rain, averaging 77 mm (3 in). With rain spread across many days but low totals, showers are typically short and light rather than heavy.
Temperature in Belfast in May
Daytime temperatures in Belfast reach 15°C (59°F) in May, dropping to 8°C (46°F) at night. Temperatures can feel cooler in the morning and evening, so layering is often the best approach. With overnight lows of 8°C (46°F), nights are cold. The cold air does make for deep, comfortable sleep if you have enough blankets.
Sunshine in Belfast in May
You can expect a moderate amount of sunlight, with approximately 184 hours. This means a pleasant mix of sun and overcast.
Wind Speed in Belfast in May
In May, average wind speeds reach 4 m/s (8 knots), leading to light to moderate breezes. Conditions vary from day to day, with both calm and windier periods.
Average water temperature in May
At 9°C (48°F), the water is very cold. Most people find it too uncomfortable for anything beyond a brief wade.If your ideal day consists of dry skies and pleasant temperatures, July and August typically offer the best circumstances for Belfast.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United Kingdom, check out our Belfast's climate page.
Belfast Temperature in May
Min Temperature
8°C (46°F)
Max Temperature
15°C (59°F)
Water Temperature
9°C (48°F) *
Chance of Rain
54%
Precipitation
77 mm (3 in)
Rainy days
16 days
Humidity
89% *
Windspeed
4 m/s (8 knots) *
Sunshine
184 hours *
Percentage Sunshine
39% *
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Belfast typically stay consistent throughout May, with daily highs averaging around 15°C (59°F). Nights are cold, with lows typically ranging from 6°C (43°F) to 9°C (48°F).
Average temperatures in May
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in May
Historical weather for Belfast in May
Browse day-by-day weather records for Belfast spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Belfast historical weather extremes in May
Based on 50 years of weather observations (1976-2026), these are the most extreme conditions recorded in Belfast.
- The warmest day in May was on May 25, 2012, with a maximum of 25°C (77°F).
- Belfast experienced its chilliest May day on May 14, 1993, reaching only 5°C (41°F).
- The lowest overnight temperature recorded in May was -2°C (28°F) (May 4, 1979).
- The wettest day in May Belfast was on May 3, 2015 with 24 mm (0.9 in) of precipitation.
Best Places in the United Kingdom in May
Find out more about the weather in the United Kingdom and which places have the best travel conditions in this month. See all of the United Kingdom in May →
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What to Wear in Belfast in May
The weather can swing between comfortable and chilly in May, so flexibility is key. Pack a variety of tops, at least one warm layer, and both shorts and long pants. This gives you options no matter what the day brings. Wet weather is likely, so pack waterproof gear for multiple rainy days. Expect water temperatures of around 9°C (48°F), which is definitely too cold for comfortable swimming. Your luggage space is better used for other items. Sunglasses could come in handy during the sunnier parts of your trip.What To Do in Belfast in May
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United Kingdom, check out our Belfast's climate page.
Temperature Rainfall Sunshine Humidity Wind Speed Water Temp
See the full Belfast climate overview or explore weather in the United Kingdom.
