Swimming in Letterkenny in september 2025: Average sea temperature in september and tide times in september 2025
Average sea temperature in Letterkenny in september 2025.
In september, according to seasonal norms, the sea temperature in Letterkenny is:
Minimum: 56°F
Average: 58°F
Maximum: 60°F
Other useful seasonal weather averages in september:
- Outside temperature: 49°F to 61°F
- Most common weather: "Cloudy"
- The wind blows at 5mph
- It rains a total of 2.3in, over 3 day(s).
Should we swim in Letterkenny in september?
No... The water temperature in Letterkenny in september is freezing
You won't be able to swim in Letterkenny in september! The water temperature is freezing, reaching as low as 56°F (and only 60°F at best)! Our advice: if you are going to Letterkenny this month, plan to sightsee and forget the beach!
Note also that in september, the climate is bad with an average outside temperature of 55°F, 2.3in of precipitation (over 3 days) and 95.18 % humidity.
Water and normal seasonal temperatures in Letterkenny in september
| September | |||
| Average sea temperature | 58°F | ||
| Minimum sea temperature | 56°F | ||
| Maximum sea temperature | 60°F | ||
| Average outside temperature | 56°F | ||
| Maximum outside temperature | 61°F | ||
| Minimum outside temperature | 50°F | ||
| Wind speed | 11.8mph | ||
| Wind temperature | 47°F | ||
| Precipitation | 2.3in | ||
| Number of days of rain | 3 jour(s) (8%) | ||
| Humidity | 96% | ||
| Visibility in kilometers | 7.44km | ||
| Cloud cover | 67% | ||
| Our opinion | freezing swimming |
Chart of the tides in september 2025
Tide times in september 2025 in Letterkenny
Swim elsewhere in Ireland in september
| City | Average T° | Min. T° | Max. T° | Our opinion | Dublin in september | 59°F | 60°F | freezing swimming | Cork in september | 61°F | 64°F | cold swimming | Galway in september | 59°F | 61°F | freezing swimming | Belmullet in september | 59°F | 62°F | freezing swimming | Connemara National Park in september | 59°F | 62°F | freezing swimming | Dingle in september | 59°F | 63°F | cold swimming | Dundalk in september | 59°F | 60°F | freezing swimming | Dungloe in september | 58°F | 60°F | freezing swimming | Killybegs in september | 58°F | 60°F | freezing swimming | Achill Island in september | 59°F | 61°F | freezing swimming | Cliffs of Moher in september | 59°F | 62°F | cold swimming | Donegal in september | 58°F | 60°F | freezing swimming | Waterford in september | 61°F | 63°F | cold swimming | Wexford in september | 60°F | 61°F | cold swimming | Sligo in september | 59°F | 61°F | freezing swimming | Westport in september | 59°F | 62°F | freezing swimming |