Donegal Weather in May
May in Donegal sees daytime temperatures around 15°C (59°F) and lows of 7°C (45°F) at night. With around 101 mm (4 in) of rainfall expected, it's worth packing a rain jacket.
Rainfall in Donegal in May
Historically, May sees about 19 days of rain, with a monthly average of 101 mm (4 in). Expect frequent rainfall this month, and not just light drizzle. When it rains, it tends to come down hard.
Temperature in Donegal in May
If you're visiting Donegal in May, expect highs of 15°C (59°F) and overnight lows around 7°C (45°F). The difference between afternoon and evening temperatures is usually noticeable. Nights fall to 7°C (45°F), which is cold enough to feel it indoors too. A good thick duvet makes all the difference for a comfortable night's sleep.
Sunshine in Donegal in May
Expect a lot of sunshine this month, with about 203 hours of sun. These sunny conditions add to the overall experience.Our weather planner can help you find worldwide destinations with pleasant weather during this period. July and August typically offer the best weather for Donegal.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Ireland, check out our Donegal's climate page.
Donegal Temperature in May
Min Temperature
7°C (45°F)
Max Temperature
15°C (59°F)
Chance of Rain
63%
Precipitation
101 mm (4 in)
Rainy days
19 days
Sunshine
203 hours *
Percentage Sunshine
*
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Donegal 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
Historical weather for Donegal in May
Browse day-by-day weather records for Donegal spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Donegal historical weather extremes in May
Based on 50 years of weather observations (1976-2026), these are the most extreme conditions recorded in Donegal.
- On May 31, 1997, temperatures climbed to 26°C (79°F), marking the warmest May day on record.
- Donegal experienced its chilliest May day on May 1, 1996, reaching only 6°C (43°F).
- Nighttime temperatures dropped to -2°C (28°F) on May 3, 1996, marking the coldest May night on record.
Best Places in Ireland in May
Find out more about the weather in Ireland and which places have the best travel conditions in this month. See all of Ireland in May →
perfect weather
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tolerable
unpleasant
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What to Wear in Donegal 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. Expect heavy rainfall, so bring good rain protection and waterproof bags. And with plenty of sunshine hours, don’t forget sunglasses, sunscreen, and maybe a sun hat.What To Do in Donegal 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 Ireland, check out our Donegal's climate page.
See the full Donegal climate overview or explore weather in Ireland.
