Letterkenny weather in December
Temperature, sea and sunshine in December: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in December
Poor
Best time to visit: April – June
What is the weather like in Letterkenny in December?
In December, Letterkenny is cold: daytime highs average 8 °C, and nights cool down to about 3 °C. The sea averages 10.3 °C – swimming is only for the hardy. The sun is scarce, with only about 1 hours a day. It rains often – on about 19 days, adding up to 112 mm. All in all, December is not an ideal month for a holiday in Letterkenny.
December compared
How the weather changes from November to January. Tap a month to open it.
| NovemberNov | DecemberDec | JanuaryJan | |
|---|---|---|---|
| Score | 0 | 0 | 0 |
| Day | 9° | 8° | 7° |
| Night | 5° | 3° | 3° |
| Sea | 12° | 10° | 9° |
| Sun | 2 h | 1 h | 1 h |
| Rain days | 19 | 19 | 18 |
More details for December
- Daylight
- 7 h 14 min08:49 – 16:03
- UV index
- 0 · lowclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 26 km/haverage daily peakAll months
- Cloud cover
- 80 %on averageAll months
- Hot days
- 0 days30 °C or more
- Snow days
- 1 day1 cm or more of fresh snow
- Time zone
- UTC+0Europe/Dublin
How the score comes together
- Temperatureweight 35 %0 %
- Seaweight 25 %0 %
- Sunshineweight 20 %0 %
- 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 December
- Warm jacket
- Rain jacket or umbrella
Letterkenny in December: quick answers
Is Letterkenny hot in December?
No. In December, Letterkenny is cold: daytime highs average 8 °C and nights drop to about 3 °C.
Can you swim in Letterkenny in December?
Only if you don't mind cold water: in December the sea averages just 10.3 °C. Comfortable swimming temperatures are not reached at any time of year.
Does it rain much in Letterkenny in December?
It rains often – on about 19 days, adding up to 112 mm.
Letterkenny month by month
The whole year in LetterkennyAll destinations: IrelandWhere to go in DecemberSea temperature in December
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