Weather in Galway in December
Ireland · 20-year averages, December
The month to avoid. Of the twelve, December is the one to avoid. Highs sit at 7.8 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.
December ranks 11 of 12 — near the bottom of Galway's year. June is the month that works, and the swing between the two is 41 points, which is a different holiday rather than a slightly better one.
Rain on 19 days, 3 of them heavy. Enough to need a plan B, not enough to need a plan around it. Layers, and a genuinely waterproof outer — at 7.8 °C the difference between a good day and a miserable one is entirely down to what you are wearing.
What the averages hide
Averages flatten a month, and this one hides a few things: 4 nights fall below freezing; the day barely swings — 4.3 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest December day reached 13.8 °C and the coldest night fell to -7.3 °C, and the wettest single day dropped 38 mm — roughly 34% of the month's rain in one day.
December is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest December on record still delivered 252 mm against 47 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 113 mm average is a reasonable planning figure, not a promise.
Wind is light at 13.6 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 95%, which at 7.8 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.
How December sits in the year
Temperatures hold steady either side: 9.9 °C in November, 7.8 here, 7.5 in January. Nothing about the timing within the month matters much.
Daylight in December
December sits at the dark end of Galway's year — 7.6 hours of daylight against 16.9 at midsummer, losing 0.4 hours across the month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.
An inland climate
Despite being inland, the year stays fairly even: 17.1 °C between the year's warmest afternoons and coldest nights.
How busy it gets
Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.
Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.
December in Galway versus nearby
If Galway is one option among several, the nearby comparison is worth making. Cork is close enough to be a coin toss — within a degree on temperature, 1 day more rain. Dublin is close enough to be a coin toss — within a degree on temperature, 1 day less rain.
So: December is a compromise. June is 40 points better and is what Galway is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.
Every month in Galway
| Month | High °C | Low °C | Rain days | Rain mm | Humidity % | Daylight h | Score |
|---|---|---|---|---|---|---|---|
| January | 7.5 | 3 | 20 | 108 | 94 | 8 | 25 |
| February | 7.9 | 2.7 | 16 | 84 | 93 | 9.8 | 33 |
| March | 9.7 | 3.1 | 16 | 81 | 89 | 11.8 | 39 |
| April | 12.9 | 4.8 | 14 | 68 | 84 | 13.9 | 52 |
| May | 15.8 | 7.4 | 17 | 81 | 80 | 15.8 | 57 |
| June | 18.6 | 10 | 17 | 89 | 78 | 16.9 | 66 |
| July | 19.8 | 11.5 | 20 | 97 | 81 | 16.5 | 65 |
| August | 19.1 | 11.4 | 20 | 105 | 83 | 14.9 | 62 |
| September | 17.3 | 10 | 16 | 86 | 86 | 12.8 | 63 |
| October | 13.6 | 7.6 | 19 | 104 | 90 | 10.7 | 46 |
| November | 9.9 | 5.1 | 19 | 118 | 94 | 8.7 | 33 |
| December | 7.8 | 3.5 | 19 | 113 | 95 | 7.6 | 26 |
See all twelve months in Galway, or where else to go in December.
Planning the rest of the trip
- Flight time to Galway how long you are actually in the air
- Galway time zone and the difference from home
- Days until your trip count down to the departure date