Donegal — Water Temperature in May

Water Temperature Range

9°C

minimum

11°C

average

13°C

maximum

Get instant access to real-time water temperatures for this and all other locations with our iOS and Android apps.

Water Temperature Chart for Month

The chart shows the average daily water temperature for each day of the month based on historical data.

Table of Water Temperatures by Day of the Month for Previous Years

Day	2026	2025	2024	2023
MAY 1	-10°C	11°C	10°C	10°C
MAY 2	12°C	10°C	9°C	10°C
MAY 3	12°C	10°C	11°C	10°C
MAY 4	12°C	11°C	11°C	10°C
MAY 5	12°C	11°C	11°C	10°C
MAY 6	12°C	11°C	11°C	10°C
MAY 7	11°C	11°C	11°C	10°C
MAY 8	12°C	11°C	11°C	10°C
MAY 9	12°C	11°C	11°C	10°C
MAY 10	12°C	11°C	11°C	10°C
MAY 11	12°C	11°C	11°C	10°C
MAY 12	12°C	11°C	12°C	11°C
MAY 13	12°C	11°C	12°C	10°C
MAY 14	12°C	11°C	12°C	11°C
MAY 15	11°C	11°C	12°C	11°C
MAY 16	11°C	11°C	11°C	11°C
MAY 17	11°C	11°C	13°C	11°C
MAY 18	11°C	12°C	12°C	11°C
MAY 19	11°C	11°C	12°C	12°C
MAY 20	11°C	12°C	13°C	12°C
MAY 21	11°C	11°C	13°C	11°C
MAY 22	12°C	11°C	13°C	11°C
MAY 23	12°C	11°C	13°C	11°C
MAY 24	12°C	11°C	13°C	11°C
MAY 25	12°C	11°C	13°C	11°C
MAY 26	13°C	12°C	13°C	11°C
MAY 27	13°C	12°C	13°C	11°C
MAY 28	14°C	11°C	13°C	11°C
MAY 29	13°C	12°C	12°C	12°C
MAY 30	14°C	12°C	12°C	12°C
MAY 31	14°C	12°C	12°C	12°C

May: Climate and Swimming Opportunities

Average Night Air Temperature

7°C

Average Day Air Temperature

14°C

Precipitation Amount per Month

65 mm

Number of Rainy Days

Daylight per Day

16 hrs

Sunshine per Day

6 hrs

Average Wind Speed

17 km/h

Average Humidity

84%

With such a ratio between the average monthly temperatures of water and air, swimming feels very cold and is only for cold-water enthusiasts. Most people will prefer just a brief splash, because warming up afterward can take time.