Climate and monthly weather forecast
Killarney, Ireland

Nestled in the south-west of Ireland, Killarney experiences a Marine west coast climate, also classified as Cfb in the Köppen climate classification system. This implies a dominantly mild and temperate weather throughout the year, marked by warm summers and cool winters. Regardless of the season, the city remains relatively damp, with consistent rainfall making up a significant constituent of its climate profile.

Observed climate data reveals minimal temperature divergence year-round. A relatively moderate temperature range prevails, with winter lows in January and February hovering around 3°C (37.4°F), whereas the peak summer months of July and August record an average of 18°C (64.4°F). This constant temperature trend casts a predictability over the weather, making adaptability less of a challenge for visitors or dwellers.

Rainfall, while being substantial all year, follows a slightly fluctuating pattern. December reports the highest average rainfall of 166mm (6.54"), quite similar to January with 160mm (6.3"). A less intense rain spells can be expected during the summer months, with rainfall numbers dropping down to 74mm (2.91") in June. The number of rainy days also exhibit this variability, with slightly lower counts in the relatively drier months.

Sunshine and daylight hours experience significant variations, reaching their maximum levels during the summer. June offers around 16.6 daylight hours and 5 sunshine hours, whereas December presents brief spells of daylight at 7.8 hours and just one sunshine hour. However, the UV index remains rather constant, peaking at 6 in the sunnier summer months.

Those seeking an ideal mix of conditions might find the late spring and early summer months the most favourable. Between May and July, the city enjoys lengthy daylight hours, ranging from 15.7 hours to 16.6 hours. The temperatures remain pleasant, reflecting an ambient range of 14°C (57.2°F) to 18°C (64.4°F). Moreover, these months also have relatively lower rain intensity, with rainfall averaging from 74mm (2.91") to 84mm (3.31").

Travelers might want to reconsider planning a trip during December, where the weather conditions are most adverse. This month records the highest rainfall figures at 166mm (6.54"), coupled with a larger frequency of rainy days and fewest daylight hours at 7.8 hours. Furthermore, the temperatures estimated a low of 4°C (39.2°F), which might not be appealing to travelers.

Spring, extending from March to May, unveils a transitional phase in Killarney’s weather. Temperatures embark on a gentle ascent, with averages moving from 10°C (50°F) in March to 14°C (57.2°F) in May. Simultaneously, the daylight hours expand, increasing from 11.9 hours to 15.7 hours. Rainfall, although tapering, still remains significant but less intense, with an average drop from 113mm (4.45") to 84mm (3.31").

July and August, marking the heart of summer, arrive with the highest average temperatures, at 18°C (64.4°F). A distinguishable feature of the season is the extended daylight hours, peaking at 16.6 hours in June, and a uniform 5 sunshine hours. Rainfall dips to its annual low, hovering around 74mm (2.91") to 77mm (3.03"), making these months an opportune time to explore the city.

Autumn in Killarney, taking place from September to November, sees a gradual dwindling of temperatures. They dip from a moderate 16°C (60.8°F) in September to a cooler 10°C (50°F) in November. The ample supply of daylight hours earlier seen in the summer also diminishes to 8.8 hours by November. Rainfall begins its ascend, reaching 149mm (5.87") by November, marking the onset of the wet season.

December ushers in winter, characterized by cold temperatures, an increase in rainfall intensity, and reduced daylight hours. Average temperatures linger in the lower bracket, around 3°C (37.4°F) to 4°C (39.2°F). Rainfall peaks at 166mm (6.54") in December, coupled with a significant count of rainy days. Simultaneously, daylight hours recede to 7.8 hours in December, presenting limited sunlit hours for outdoor activities.

Transitioning from the mild December weather, Killarney's January temperature cools down slightly, offering a chilly embrace. This month proves to be the most rain-soaked period of the year, with precipitation reaching 160mm (6.3"). Weather in January »

Heading into February, the essence of winter persists in Killarney but with reduced rainfall than the prior month, indicating the impending arrival of spring. Out of all twelve months, February ties with January for possessing the lowest UV index. Weather in February »

March in Killarney witnesses a shift in the climate as winter signs off, paving the way for spring. The city endures marginally less rainfall than February, only falling from 118mm (4.65") to 113mm (4.45"). Noticeably longer days arrive, setting the stage for the arrival of the regenerative season. Weather in March »

April ushers in the essence of spring in Killarney with warmer weather and shorter spells of rain, down to 77mm (3.03"). The UV index in this period shows a significant increase, doubling from March. The city and its residents come alive under the extended daylight. Weather in April »

May is characterized by longer, warmer days in Killarney, indicating the approach of summer. Rainfall continues to drop, drawing out the sun. Extended daylight hours and moderate temperatures provide residents and tourists multiple opportunities for daytime excursions. Weather in May »

In June, Killarney experiences a steady rise in temperatures, marking the beginning of the summer season. Sunshine is more prevalent this month, but the rainfall only slightly declines, amounting to 74mm (2.91"). June also brings the highest UV index, nudging locals and visitors to wear appropriate sun protection while venturing outside. Weather in June »

July in Killarney retains the warmth of June, continuing with the sunny disposition and boasting an equal UV index of 6. Though one might anticipate a summer dry spell, rain is quite frequent, reaching 77mm (3.03"). The sun-drenched beaches are lively, and so are the bustling city streets. Weather in July »

As the peak of summer, August features comfortable warmth, akin to July, and a nearly identical precipitation level, increasing to 97mm (3.82"). The daylight starts to shrink slightly, signaling the onset of autumn. Days are warm enough for swimming and other water-related activities but interspersed with enough rainfall to keep the surroundings lush and green. Weather in August »

September indicates the advent of autumn in Killarney, with the temperature slightly dropping from August and rainfall amounting to 117mm (4.61"). Less sunshine is seen this month, replicating the transition from summer to autumn. Weather in September »

October, the same as September, in Killarney, Ireland, is a moderate autumn month, with temperature in the range of an average low of 8°C (46.4°F) and an average high of 14°C (57.2°F). October's weather records an average high-temperature of a still refreshing 14°C (57.2°F), showing little deviation from September. Weather in October »

November brings a sharp drop in temperature, marking the transition from fall to winter. The rainfall increases to 149mm (5.87"), second only to the peak value observed in January. Days become noticeably shorter and chillier, pointing to the imminent winter. Weather in November »

As the final month of the year, December in Killarney is a crisp winter month with temperatures barely rising above single digits. The rainfall peaks yet again, almost rivalling the record rainfall of January at 166mm (6.54"). Weather in December »