The highest day temperature in September 2026 was 69°F. The lowest night temperature was 45°F. The average values for day and night temperatures during September were 61.5°F и 53.2°F respectivly.

The average sea surface temperature in September 2026 for Killarney was 63.0°F. The maximum and minimum values were 61.6°F and 64.6°F respectively.

Most of the days in September are gloomy but you can also expect sunny days.

Precipitation total in September for Killarney is 2.7 in. It makes september one of the least rainy months of the year.

The average wind speed in September is 8.0 mph. It makes September one of the most windless months of the year for Killarney.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Killarney in September is 3.9 hours.