Cool
Average highs are around 17°C, so pack for cooler days.
Weather Guide
Letterkenny, Ireland Average Monthly Weather
Weather score18Poor annual avg
Best months: July, June, August
Across the year, average daytime temperatures are around 12°C, sunshine averages 3.2h per day, and rainfall totals about 1279mm. Sea temperatures average 12°C across the year.
Annual weather
Annual averages
Temp
12°C
Rain
1279mm
Annual total
Sun
3.2h
Sea
12°C
Weather score
18
Poor avg
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Showers
Rainfall averages 98mm, so some wet days are possible.
Limited sun
Sunshine averages 4.1h per day, so this is not one of the brighter months.
Cool sea
Sea temperatures average 15°C, so the water can feel cool.
Map
Weather map
Compare Letterkenny, Ireland with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
August17°C average high
August is one of Letterkenny's hottest months, so shade and slower afternoons matter.
Warmest monthsJune to September
This stretch sets the upper range for average daytime heat.
Rain
August98mm average rain
August sits near Letterkenny's yearly rainfall average, so rain is a normal planning factor rather than an outlier.
Driest monthsFebruary to August
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
August4.1 hours average sun
August is brighter than Letterkenny's yearly average, though the strongest sunshine usually sits closer to the peak months.
Brightest monthsApril to June
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
August15°C average sea
August is one of Letterkenny's warmest sea months, when swimming comfort is usually strongest.
Warmest seaJuly to September
Sea temperatures are usually near 15°C in this stretch, so swimming comfort is at its strongest.
Weather score
August25 weather score
August is one of Letterkenny's best weather-score months, combining the strongest overall balance in the yearly averages.
Best weather monthsApril to August
These months have the strongest weather score in the monthly averages.
