Click on a day for an hourly weather forecast
The temperatures in Letterkenny in October are quite cold with temperatures between 6°C and 13°C, warm clothes are a must.
You can expect rain for roughly half of the month of October in Letterkenny. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Letterkenny in October 2025.
If you’re planning to visit Letterkenny in the near future, we highly recommend that you review the 14 day weather forecast for Letterkenny before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 6° / 1° | 9 | 18 | 4 | 78 mm | Awful | Letterkenny in January |
| February | 7° / 1° | 9 | 15 | 4 | 77 mm | Awful | Letterkenny in February |
| March | 9° / 2° | 8 | 21 | 3 | 66 mm | Awful | Letterkenny in March |
| April | 12° / 3° | 5 | 24 | 1 | 48 mm | Ok | Letterkenny in April |
| May | 14° / 5° | 6 | 25 | 0 | 69 mm | Good | Letterkenny in May |
| June | 17° / 8° | 6 | 24 | 0 | 78 mm | Good | Letterkenny in June |
| July | 18° / 10° | 7 | 24 | 0 | 90 mm | Ok | Letterkenny in July |
| August | 17° / 10° | 6 | 25 | 0 | 76 mm | Good | Letterkenny in August |
| September | 16° / 8° | 6 | 24 | 0 | 59 mm | Good | Letterkenny in September |
| October | 13° / 6° | 8 | 23 | 0 | 79 mm | Bad | Letterkenny in October |
| November | 9° / 4° | 8 | 21 | 0 | 80 mm | Bad | Letterkenny in November |
| December | 7° / 2° | 8 | 21 | 2 | 76 mm | Awful | Letterkenny in December |