March in Killarney is the sunniest month of the year. In March, the weather in Killarney is typically warm. Average daily high temperature in March is about 10 degrees above zero. On average, Killarney has 16 rainy, 7 partly cloudy, 5 cloudy, and 3 sunny days in March. The rains are usually heavy. March as well as January, February, April, and May is considered the most uncomfortable time to visit Killarney.