Letterkenny Weather in May
May in Letterkenny sees daytime temperatures around 15°C (59°F) and lows of 7°C (45°F) at night. With around 94 mm (3.7 in) of rainfall expected, it's worth packing a rain jacket.
Rainfall in Letterkenny in May
Expect around 18 days of rain based on historical data, with 94 mm (3.7 in) average. Neither particularly heavy nor particularly frequent, the rain this month is about average. A light jacket should be enough on most wet days.
Temperature in Letterkenny in May
May in Letterkenny brings typical temperatures with highs around 15°C (59°F) and lows of 7°C (45°F). A light jacket or extra layer can be useful, especially outside the warmest hours of the day. With overnight lows of 7°C (45°F), nights are cold. The cold air does make for deep, comfortable sleep if you have enough blankets.
Sunshine in Letterkenny in May
With approximately 203 hours of sunshine, the days are filled with clear skies. It makes it a perfect month for being outside.If your ideal day consists of dry skies and pleasant temperatures, May, July, August and September typically offer the best circumstances for Letterkenny.
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 Letterkenny's climate page.
Letterkenny Temperature in May
Min Temperature
7°C (45°F)
Max Temperature
15°C (59°F)
Chance of Rain
61%
Precipitation
94 mm (3.7 in)
Rainy days
18 days
Sunshine
203 hours *
Percentage Sunshine
*
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Letterkenny 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 Letterkenny in May
Browse day-by-day weather records for Letterkenny spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Letterkenny historical weather extremes in May
Our historical data for Letterkenny spans 1976 to 2026, revealing these weather extremes.
- The hottest May day on record in Letterkenny reached 25°C (77°F) (May 26, 2017).
- The coldest May day was on May 1, 1979, with a maximum of 6°C (43°F).
- Letterkenny registered its coldest May night on May 14, 2020, with temperatures dropping to -2°C (28°F).
- The heaviest May precipitation occurred on May 3, 2015, when 26 mm (1 in) of precipitation fell.
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 Letterkenny 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. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.What To Do in Letterkenny 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 Letterkenny's climate page.
See the full Letterkenny climate overview or explore weather in Ireland.
