Donegal weather in August
Temperature, sea and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Poor
Best time to visit: April – June
What is the weather like in Donegal in August?
In August, Donegal is mild: daytime highs average 17 °C, and nights cool down to about 12 °C. The sea averages 15.6 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. It rains often – on about 20 days, adding up to 114 mm. All in all, August is not an ideal month for a holiday in Donegal.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 5 | 6 | 5 |
| Day | 18° | 17° | 16° |
| Night | 12° | 12° | 11° |
| Sea | 15° | 16° | 15° |
| Sun | 5 h | 5 h | 4 h |
| Rain days | 19 | 20 | 16 |
More details for August
- Daylight
- 15 h 1 min06:07 – 21:08
- UV index
- 5 · moderateclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 21 km/haverage daily peakAll months
- Cloud cover
- 80 %on averageAll months
- Hot days
- 0 days30 °C or more
- Snow days
- 0 days1 cm or more of fresh snow
- Time zone
- UTC+1Europe/Dublin
How the score comes together
- Temperatureweight 35 %0 %
- Seaweight 25 %0 %
- Sunshineweight 20 %30 %
- Few rainy daysweight 20 %0 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in August
- Sunscreen
- A jumper for the evenings
- Rain jacket or umbrella
Donegal in August: quick answers
Is Donegal hot in August?
No. In August, Donegal is mild: daytime highs average 17 °C and nights drop to about 12 °C.
Can you swim in Donegal in August?
Only if you don't mind cold water: in August the sea averages just 15.6 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Donegal in August?
It rains often – on about 20 days, adding up to 114 mm.
Donegal month by month
The whole year in DonegalAll destinations: IrelandWhere to go in AugustSea temperature in August
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences