AI-generatedLetterkenny at a glance
- Best time
- Apr – Jun
- Warmest month
- Jul · 18°
- Warmest sea
- Aug · 15.3°
- Sunshine a year
- 1,250 h
- Rain a year
- 1,175 mm
- Climate
- Maritime
- Time zone
- UTC+0 / UTC+1
- Elevation
- 8 m
Climate in Letterkenny
Letterkenny has a maritime climate with moderate summers and cool, often grey winters. July is the warmest month with average highs of 18 °C, while January is the coolest at 7 °C. With around 1,250 hours of sunshine a year, Letterkenny is rather dull; May is the sunniest month with 5.9 hours a day.
Holiday weather through the year
Weather in October
Holiday weather in October
Poor
Best time to visit: April – June
Keep in mindFrequent rain
A typical day in October
- Morning, 08:00: about 8°
- Midday, 13:00: about 12°
- Afternoon, 16:00: about 13°
- Evening, 20:00: about 11°
- Night, 23:00: about 10°
07:5818:35
Cold evenings: bring a warm jacket.
Estimated from the average high and low: coolest around sunrise, warmest in mid-afternoon.
Light for photos in October
- Golden hour
- Morning 07:36–08:48 · evening 17:45–18:57
- Blue hour
- Morning 07:22–07:36 · evening 18:57–19:11
Golden hour: the sun between 4° below and 6° above the horizon; blue hour: 6° to 4° below it. Times for the 15th of the month; mountains and clouds shift the light.
What is the weather like in Letterkenny in October?
In October, Letterkenny is cool: daytime highs average 13 °C, and nights cool down to about 8 °C. The sea averages 13.3 °C – swimming is only for the hardy. The sun is scarce, with only about 3 hours a day. It rains often – on about 18 days, adding up to 112 mm. All in all, October is not an ideal month for a holiday in Letterkenny.
More details for October
- Daylight
- 10 h 37 min07:58 – 18:35
- UV index
- 1 · lowclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 24 km/haverage daily peakAll months
- Cloud cover
- 79 %on averageAll months
- Hot days
- 0 days30 °C or more
- Snow days
- 0 days1 cm or more of fresh snow
- Time zone
- UTC+1Europe/Dublin
How the score comes together
- Temperatureweight 35 %0 %
- Seaweight 25 %0 %
- Sunshineweight 20 %0 %
- Few rainy daysweight 20 %0 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in October
- A jumper for the evenings
- Rain jacket or umbrella
Sea temperature in Letterkenny
Monthly sea surface temperature with the range of cooler and warmer years.
8 in 10 years: 12.7 – 13.8 °C
Swimming season: Never above 20 °C
- cold
- fresh
- refreshing
- pleasant
- warm
- very warm
The sea temperature in Letterkenny ranges from 8.6 °C in February to 15.3 °C in August. Even at its warmest the sea stays below 20 °C, so swimming is bracing at best.
The sea warms up slowly: it is warmest in August, while the air already peaks in July. From October to February the sea is even warmer than the afternoon air. The sea temperature varies from year to year: in August, eight out of ten years were between 14.6 and 16.1 °C.
| Month | Average | Cool year | Warm year | Feels |
|---|---|---|---|---|
| JanuaryJan | 9.2° | 8.7° | 9.6° | cold |
| FebruaryFeb | 8.6° | 8.0° | 9.1° | cold |
| MarchMar | 8.6° | 7.9° | 9.2° | cold |
| AprilApr | 9.4° | 8.6° | 9.9° | cold |
| MayMay | 11.1° | 10.1° | 12.1° | cold |
| JuneJun | 13.2° | 12.2° | 14.5° | cold |
| JulyJul | 14.7° | 13.7° | 15.8° | cold |
| AugustAug | 15.3° | 14.6° | 16.1° | cold |
| SeptemberSep | 14.7° | 14.0° | 15.3° | cold |
| OctoberOct | 13.3° | 12.7° | 13.8° | cold |
| NovemberNov | 11.8° | 11.0° | 12.5° | cold |
| DecemberDec | 10.3° | 9.7° | 10.8° | cold |
Sunshine hours in Letterkenny
Average hours of bright sunshine per day, next to the length of the day. Tap a month to select it.
In October, the sun shines for about 2.7 of 10.6 hours of daylight in Letterkenny, 25 % of the day.
Sunshine hours: estimated from radiation data (ERA5, 1996–2025) and calibrated against measured station values; no weather station is close enough here. Daylight is the time from sunrise to sunset on the 15th of the month.
UV index in Letterkenny
How strong the sun is at noon, month by month, and how quickly unprotected skin burns.
- Clear-sky UV in October
- 1 · lowLittle protection needed; sunglasses on bright days.
The sun is strongest in June (UV 7).
Minutes until sunburn in October
- Very fair skin
- about 95 min
- Fair skin
- about 115 min
- Light brown skin
- over 2 h
- Olive skin
- over 2 h
Rough guide for unprotected skin at noon under a clear sky; clouds lengthen it, water, sand and snow shorten it. Sunscreen extends the time only partly.
Monthly values: clear-sky noon estimate from the sun's angle, ozone and altitude. UV today: Open-Meteo forecast.
Rain in Letterkenny: rainy days and rainfall
A rainy day is a day with at least 1 mm of rain or snow; the amount is what falls in the whole month. Tap a month to select it.
In October, Letterkenny has about 18 rainy days with 112 mm of rain in total.
Wind and clouds in Letterkenny
How breezy and how cloudy Letterkenny is through the year. Tap a month to select it on the whole page.
Wind
Typical daily peak of the wind in km/h: what the afternoon breeze usually reaches, not the gusts.
In October, the wind in Letterkenny typically peaks at 24 km/h during the day: Beaufort 4, moderate breeze.
Breezy months for windsurfing and kiting
From Beaufort 4 (20 km/h) the daily breeze is usually enough for windsurfing and often for kiting: Aug – Jun.
Clouds
Average share of the sky covered by cloud, day and night.
In October, cloud covers on average 79 % of the sky over Letterkenny: mostly cloudy, with about 2.7 hours of sunshine a day.
Wind: mean daily maximum of the hourly wind 10 m above ground (ERA5, 1996–2025). Gusts are stronger, and the model grid of about 28 km smooths out local effects such as capes and valley winds. Clouds: mean total cloud cover of all layers over day and night (ERA5, 1996–2025). Thin high cloud counts as cover even when the sun still shines through.
Climate through the year
Long-term monthly averages. Tap a month to see its details.
Nights and sleep in Letterkenny
How warm the nights get in each month, from the mean night-time low. Tap a month for details.
- Cold 0–8°
- Cool 8–15°
CoolOctober: nights around 8°. A duvet at night and a jumper for the evening.
The coolest nights are in January (3°), the warmest in August (12°). Nights fall below 8 °C on average from November to April, so the room should be heated.
Temperatures through the year
Average daytime high, night-time low and sea temperature per month.
| Month | Score | Day | Night | Sea | Sun | Rain days | Rain mm |
|---|---|---|---|---|---|---|---|
| JanuaryJan | 0 | 7° | 3° | 9.2° | 1.4 h | 18 | 104 |
| FebruaryFeb | 2 | 8° | 3° | 8.6° | 2.4 h | 16 | 96 |
| MarchMar | 3 | 9° | 3° | 8.6° | 3.2 h | 16 | 81 |
| AprilApr | 10 | 12° | 5° | 9.4° | 5.0 h | 16 | 78 |
| MayMay | 12 | 15° | 8° | 11.1° | 5.9 h | 16 | 90 |
| JuneJun | 9 | 17° | 10° | 13.2° | 5.0 h | 16 | 94 |
| JulyJul | 5 | 18° | 12° | 14.7° | 4.5 h | 18 | 103 |
| AugustAug | 5 | 18° | 12° | 15.3° | 4.6 h | 18 | 107 |
| SeptemberSep | 4 | 16° | 10° | 14.7° | 3.4 h | 16 | 89 |
| OctoberOct | 0 | 13° | 8° | 13.3° | 2.7 h | 18 | 112 |
| NovemberNov | 0 | 9° | 5° | 11.8° | 1.7 h | 19 | 110 |
| DecemberDec | 0 | 8° | 3° | 10.3° | 1.3 h | 19 | 112 |
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences
54.95° N, 7.73° W · 8 m · Europe/Dublin
Best time to visit Letterkenny
The best time to visit Letterkenny is from April to June. The sea stays too cool for a classic beach holiday: even in August it only reaches 15.3 °C. The wettest month is October with 112 mm of precipitation.
Letterkenny through the seasons
How the weather changes over the seasons, with averages for each.
Letterkenny in spring
Mar – May
Poor
- 9–15 °C by day
- Sea 10 °C
- 5 h of sun a day
- 48 rainy days in all
Letterkenny in summer
Jun – Aug
Poor
- 17–18 °C by day
- Sea 14 °C
- 5 h of sun a day
- 53 rainy days in all
Letterkenny in autumn
Sep – Nov
Poor
- 9–16 °C by day
- Sea 13 °C
- 3 h of sun a day
- 53 rainy days in all
Letterkenny in winter
Dec – Feb
Poor
- 7–8 °C by day
- Sea 9 °C
- 2 h of sun a day
- 53 rainy days in all
Find your perfect month
Tell us what you like and we rate every month in Letterkenny for you.
Your best months: April – June
Based on the climate averages; tap a month to see its details.
Compare two months in Letterkenny
Pick two months to see how the weather differs. A tick marks the clearly better value; for temperatures it depends on your plans.
May has the better holiday weather in Letterkenny: score 12 against 0. In May, days are 2 °C warmer than in October. The sea is 2 °C cooler in May. May has 2 fewer rainy days. The sun shines 3 hours longer a day in May.
| Month | October | May |
|---|---|---|
| Weather score | 0 | 12better |
| Day high | 13° | 15° |
| Night low | 8° | 8° |
| Sea | 13.3° | 11.1° |
| Sunshine | 2.7 h | 5.9 hbetter |
| Rainy days | 18 | 16better |
| Rainfall | 112 mm | 90 mmbetter |
Based on the climate averages 1996–2025.
Which month for what?
Beach & swimming
No month
Sea from 21 °C, warm and mostly dry
Sightseeing & hiking
No month
15–28 °C and not too much rain
Rainy months
All year
12 or more rainy days
Letterkenny month by month
The typical weather for every month at a glance.
0January7° · Sea 9° · 1 h
In January, Letterkenny is cold: daytime highs average 7 °C, and nights cool down to about 3 °C. The sea averages 9.2 °C – swimming is only for the hardy. The sun is scarce, with only about 1 hours a day. It rains often – on about 18 days, adding up to 104 mm. All in all, January is not an ideal month for a holiday in Letterkenny.
Letterkenny in January2February8° · Sea 9° · 2 h
In February, Letterkenny is cold: daytime highs average 8 °C, and nights cool down to about 3 °C. The sea averages 8.6 °C – swimming is only for the hardy. The sun is scarce, with only about 2 hours a day. It rains often – on about 16 days, adding up to 96 mm. All in all, February is not an ideal month for a holiday in Letterkenny.
Letterkenny in February3March9° · Sea 9° · 3 h
In March, Letterkenny is cold: daytime highs average 9 °C, and nights cool down to about 3 °C. The sea averages 8.6 °C – swimming is only for the hardy. The sun is scarce, with only about 3 hours a day. It rains often – on about 16 days, adding up to 81 mm. All in all, March is not an ideal month for a holiday in Letterkenny.
Letterkenny in March10April12° · Sea 9° · 5 h
In April, Letterkenny is cool: daytime highs average 12 °C, and nights cool down to about 5 °C. The sea averages 9.4 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. It rains often – on about 16 days, adding up to 78 mm. All in all, April is not an ideal month for a holiday in Letterkenny.
Letterkenny in April12May15° · Sea 11° · 6 h
In May, Letterkenny is cool: daytime highs average 15 °C, and nights cool down to about 8 °C. The sea averages 11.1 °C – swimming is only for the hardy. Expect around 6 hours of sunshine a day. It rains often – on about 16 days, adding up to 90 mm. All in all, May is not an ideal month for a holiday in Letterkenny.
Letterkenny in May9June17° · Sea 13° · 5 h
In June, Letterkenny is mild: daytime highs average 17 °C, and nights cool down to about 10 °C. The sea averages 13.2 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. It rains often – on about 16 days, adding up to 94 mm. All in all, June is not an ideal month for a holiday in Letterkenny.
Letterkenny in June5July18° · Sea 15° · 5 h
In July, Letterkenny is mild: daytime highs average 18 °C, and nights cool down to about 12 °C. The sea averages 14.7 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. It rains often – on about 18 days, adding up to 103 mm. All in all, July is not an ideal month for a holiday in Letterkenny.
Letterkenny in July5August18° · Sea 15° · 5 h
In August, Letterkenny is mild: daytime highs average 18 °C, and nights cool down to about 12 °C. The sea averages 15.3 °C – swimming is only for the hardy. Expect around 5 hours of sunshine a day. It rains often – on about 18 days, adding up to 107 mm. All in all, August is not an ideal month for a holiday in Letterkenny.
Letterkenny in August4September16° · Sea 15° · 3 h
In September, Letterkenny is cool: daytime highs average 16 °C, and nights cool down to about 10 °C. The sea averages 14.7 °C – swimming is only for the hardy. The sun is scarce, with only about 3 hours a day. It rains often – on about 16 days, adding up to 89 mm. All in all, September is not an ideal month for a holiday in Letterkenny.
Letterkenny in September0October13° · Sea 13° · 3 h
In October, Letterkenny is cool: daytime highs average 13 °C, and nights cool down to about 8 °C. The sea averages 13.3 °C – swimming is only for the hardy. The sun is scarce, with only about 3 hours a day. It rains often – on about 18 days, adding up to 112 mm. All in all, October is not an ideal month for a holiday in Letterkenny.
Letterkenny in October0November9° · Sea 12° · 2 h
In November, Letterkenny is cold: daytime highs average 9 °C, and nights cool down to about 5 °C. The sea averages 11.8 °C – swimming is only for the hardy. The sun is scarce, with only about 2 hours a day. It rains often – on about 19 days, adding up to 110 mm. All in all, November is not an ideal month for a holiday in Letterkenny.
Letterkenny in November0December8° · Sea 10° · 1 h
In December, Letterkenny is cold: daytime highs average 8 °C, and nights cool down to about 3 °C. The sea averages 10.3 °C – swimming is only for the hardy. The sun is scarce, with only about 1 hours a day. It rains often – on about 19 days, adding up to 112 mm. All in all, December is not an ideal month for a holiday in Letterkenny.
Letterkenny in DecemberLetterkenny compared
Put Letterkenny side by side with another destination.
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Letterkenny vs. Derry
In October the holiday weather in Letterkenny and Derry is about equally good (score 0 vs. 1). During the day it is about as warm in Derry as in Letterkenny. The sea is about equally warm.
| in October | Letterkenny | Derry |
|---|---|---|
| Holiday score | 0 | 1 |
| Daytime high | 13° | 13° |
| Sea | 13° | 13° |
| Sunshine | 3 h | 3 h |
| Rainy days | 18 | 17 |
| Best time | Apr – Jun | Apr – Jun |
Through the year
Ireland in October: the best places
In October, Letterkenny ranks 16 of 18 destinations in this country.
- Dublin14°14°40
- 2Kilkenny14°39
- 3Cork14°14°39
- 4Waterford14°37
- 5Killarney14°36
- 6Limerick14°34
- 7Dún Laoghaire14°14°9
- 8Bray14°14°9
- 16LetterkennyThis page13°13°0
Planning a trip to Letterkenny
Weather for your travel dates
Pick your arrival and length of stay, and we sum up the weather to expect.
Letterkenny in the school holidays
How the weather suits the usual holiday periods. Dates vary by school and region, so each holiday uses the months it usually falls in.
Letterkenny has its best school-holiday weather during May half-term (score 11) and its weakest during October half-term (score 0).
- 8
Easter holidays
Mar – Apr
Poor
- 11 °C by day
- Sea 9 °C
- 4.5 h of sun a day
- 16 rainy days a month
Keep in mind: Frequent rain
- 11
May half-term
May – Jun
PoorBest holidays
- 15 °C by day
- Sea 12 °C
- 5.7 h of sun a day
- 16 rainy days a month
Keep in mind: Frequent rain
- 5
Summer holidays
Jul – Aug
Poor
- 18 °C by day
- Sea 15 °C
- 4.6 h of sun a day
- 18 rainy days a month
Keep in mind: Frequent rain
- 0
October half-term
Oct
Poor
- 13 °C by day
- Sea 13 °C
- 2.7 h of sun a day
- 18 rainy days a month
Keep in mind: Frequent rain
- 0
Christmas holidays
Dec – Jan
Poor
- 7 °C by day
- Sea 10 °C
- 1.4 h of sun a day
- 18 rainy days a month
Keep in mind: Frequent rain
Based on the climate averages 1996–2025.
Getting there
Flying from
- Nonstop flight
- about 1 h 15 min
- Distance
- 620 km
- Time zone
- UTC+1
- Jet lag
- Hardly any (under 3 h)
Estimated from the straight-line distance: 30 minutes for take-off and landing plus 830 km/h cruising speed.
Frequently asked questions about Letterkenny
When is the best time to visit Letterkenny?
The best time to visit Letterkenny is from April to June. That is when the holiday weather score, which combines temperature, sea, sunshine and rain, is highest.
How warm is the sea in Letterkenny?
The sea temperature in Letterkenny ranges from 8.6 °C in February to 15.3 °C in August. Even at its warmest the sea stays below 20 °C, so swimming is bracing at best.
Can you swim in Letterkenny in October?
Only if you don't mind cold water: in October the sea averages just 13.3 °C. Comfortable swimming temperatures are not reached at any time of year.
What is the warmest month in Letterkenny?
July is the warmest month, with average highs of 18 °C and nights around 12 °C. January is the coolest month at 7 °C.
When does it rain most in Letterkenny?
The wettest month is October with 112 mm of precipitation. The driest month is April with 78 mm.
How many hours of sunshine does Letterkenny get?
Letterkenny gets around 1,250 hours of sunshine a year. The sunniest month is May with 5.9 hours a day; in December there are 1.3 hours a day.
What time zone is Letterkenny in?
Letterkenny uses the time zone Europe/Dublin: UTC+0 in January and UTC+1 in July.
How long is the flight from London to Letterkenny?
A nonstop flight from London to Letterkenny takes about 1 h 15 min, for a straight-line distance of about 620 km.
Which school holidays are best for Letterkenny?
Letterkenny has its best school-holiday weather during May half-term (score 11) and its weakest during October half-term (score 0). Holiday ratings (0–100): Easter holidays 8, May half-term 11, Summer holidays 5, October half-term 0, Christmas holidays 0.
Near Letterkenny
Other destinations close by.
Places with a climate like Letterkenny
Destinations whose weather through the year is closest to Letterkenny's – good alternatives.