SeasonMapKillarney weather by month
Ireland
The best time to visit Killarney is May to July — 90/100 in May, 16°C and 12 rainy days. The best season is summer, June to August (88/100 on average).
The worst month is December at 61/100 — cold, rainy, clean air. See December →
Updated September 2026 · climate normals from ERA5 reanalysis
Planning the wider trip? Best time to visit Ireland →
Killarney, month by month
Comfort score out of 100 for the kind of trip Killarney is best for, the average high, rainy days and hours of sun a day from the climate normals, and how busy it tends to be.
| Month | Score | Tier | High | Rain | Sun | Crowds | On |
|---|---|---|---|---|---|---|---|
| JanJanuary | 64 | C | 9°C | 15 d | 4 h | Busy | — |
| FebFebruary | 66 | C | 9°C | 17 d | 5 h | Busy | — |
| MarMarch | 73 | B | 10°C | 17 d | 7 h | Busy | — |
| AprApril | 82 | A | 13°C | 13 d | 9 h | Busy | 1 |
| MayMay | 90 | S | 16°C | 12 d | 11 h | Busy | 1 |
| JunJune | 88 | A | 18°C | 15 d | 10 h | Busy | — |
| JulJuly | 89 | A | 19°C | 14 d | 10 h | Peak | 2 |
| AugAugust | 86 | A | 19°C | 15 d | 9 h | Peak | 1 |
| SepSeptember | 81 | A | 17°C | 15 d | 8 h | Shoulder | 1 |
| OctOctober | 74 | B | 14°C | 17 d | 6 h | Busy | 2 |
| NovNovember | 68 | C | 11°C | 17 d | 4 h | Busy | 2 |
| DecDecember | 61 | C | 9°C | 17 d | 3 h | Peak | 1 |
What's on in Killarney through the year
Festivals, natural spectacles, holidays and the seasons to watch out for — curated and sourced. The month pages carry the detail.
- April
- Rally of the Lakes1–3 MayFestival
- July
- Killarney July race festival10–25 Jul (usually)Festival
- Peak season on the Ring of Kerry1 Jul – 31 AugHoliday
- September
- Red deer rut25 Sep – 25 Oct (usually)Nature
- October
- Oakwoods turning5 Oct – 5 Nov (usually)Nature
- November
- Christmas in Killarney20 Nov – 31 Dec (usually)Festival
Crowds in Killarney in May
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
BusyRally of the Lakes, school holidays in 4 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Good to know before you go to Killarney
Real experiences from travellers' own write-ups, quoted with a link to the original.
Getting around
A guide to exploring Killarney National Park recommends booking a jaunting cart, the traditional horse-drawn carriage tour with a history dating back to Queen Victoria's 1861 visit, well in advance during summer months when demand genuinely outstrips availability. For anyone without a car, their alternative was the hop-on-hop-off Killarney Shuttle Bus, which covers the main sights across the park's roughly 103 square kilometers of lakes and forest without needing a jaunting cart booking or a rental car.