Letterkenny weather in August

In August, Letterkenny sees average daytime highs of 17°C and overnight lows near 12°C, with 105 mm of rain across 17.8 wet days and about 14.7 hours of daylight. It is the 1st-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 17°C through the month. The sky is clear or mostly clear about 3% of the time in August, and the air most often feels dry.

Daylight stretches from about 15 h 42 min at the start of August to 13 h 42 min by month's end. Set against the rest of the year, August is Letterkenny's 11th-clearest and 10th-windiest month. For the whole year in context, see Letterkenny's year-round climate.

Daytime high
17°
1st warmest
Overnight low
12°
12th coldest
Rainfall
105 mm
17.8 wet days
Daylight
14 h 42 min
5:13 AM – 7:57 PM
Cloud cover
82%
11th clearest
Wind
15 km/h
10th windiest
Solar energy
3.63 kWh/m²
Travel score
4.3
out of 10

Letterkenny is town in County Donegal, Ireland.

Density
472/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in August

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 17°C through the month.

A typical August day in Letterkenny reaches about 17°C in the afternoon and slips back to 12°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 15°C and 20°C. Set against its neighbours, August runs on par with July and about 2°C warmer than September.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
11812
21812
31812
41712
51712
61712
71712
81712
91712
101712
111712
121712
131712
141712
151712
161712
171712
181712
191712
201712
211712
221712
231711
241711
251711
261711
271711
281711
291711
301711
311711

How August really feels in Letterkenny

Once humidity and wind are folded in, August averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

August sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Letterkenny weather by month

How August compares with the rest of the year at a glance. August is the 1st-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 10818.527.60.8
Feb / 9115.91.89.31.0
Mar / 88171.311.41.5
Apr11° / 8016.10.313.82.3
May14° / 8615.9015.83.3
Jun16° / 10°92160173.9
Jul17° / 12°10118016.54.3
Aug17° / 12°10517.8014.74.3
Sep15° / 10°8815.5012.53.9
Oct13° / 10517.1010.22.8
Nov10° / 11018.80.38.11.6
Dec / 11318.11.270.9

Cloud cover in August

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 3% of the time in August.

Beyond those clear spells, partly cloudy skies cover about 10% of August, with mostly cloudy or overcast conditions the remaining 87%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
11288
21288
31288
41288
51288
61288
71387
81387
91387
101486
111486
121486
131486
141486
151486
161387
171387
181387
191387
201387
211486
221387
231387
241387
251387
261486
271486
281387
291387
301387
311387

Chance of precipitation in August

Any precipitation

Letterkenny gets around 105 mm of rain over 17.8 wet days in August. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 58% and peaks near 61% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
160
260
359
459
559
658
758
858
958
1058
1159
1259
1359
1460
1560
1660
1760
1861
1960
2060
2160
2259
2358
2457
2557
2656
2755
2854
2954
3053
3153

Humidity in August

DryComfortableHumidMuggyOppressiveMiserable

Most of August feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, August lands in the dry band about 72% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
166304
266304
366304
466304
567303
667303
767303
867303
968302
1068302
1168302
1268302
1368302
1468302
1568302
1669292
1770282
1870282
1971272
2072262
2174242
2275232
2376222
2476222
2577212
2678202
2779192
2880191
2981181
3081181
3181181

Wind in August

Winds average 15 km/h in August.

Across August, daily wind ranges from about 14 km/h on the calmest days to 15 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2815light breeze
2915light breeze
3015light breeze
3115light breeze

Sunrise & sunset in August

DaylightNight

Daylight runs from about 15 h 42 min at the start of August to 13 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 120 minutes over August. Sunrise moves from 4:45 AM to 5:41 AM, and sunset from 8:29 PM to 7:21 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
115.74:458:29
215.74:478:27
315.64:498:25
415.54:508:23
515.54:528:21
615.44:548:19
715.44:568:17
815.34:588:15
915.25:008:13
1015.25:018:11
1115.15:038:09
1215.05:058:06
1315.05:078:04
1414.95:098:02
1514.85:118:00
1614.75:137:57
1714.75:157:55
1814.65:167:53
1914.55:187:50
2014.55:207:48
2114.45:227:46
2214.35:247:43
2314.25:267:41
2414.25:287:38
2514.15:307:36
2614.05:327:33
2714.05:347:31
2813.95:367:28
2913.85:377:26
3013.75:397:23
3113.75:417:21

Solar energy in August

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in August, about 3.63 kWh/m².

For context, solar energy here swings from a low near 0.42 kWh/m² to a high of 4.85 kWh/m² in May across the year — August's 3.63 kWh/m² falls in the middle.

01234151015202531
Solar energy (kWh/m²)Level
14.0Moderate
23.9Moderate
33.9Moderate
43.9Moderate
53.9Moderate
63.9Moderate
73.8Moderate
83.8Moderate
93.8Moderate
103.8Moderate
113.8Moderate
123.7Moderate
133.7Moderate
143.7Moderate
153.7Moderate
163.6Moderate
173.6Moderate
183.6Moderate
193.6Moderate
203.5Moderate
213.5Moderate
223.5Moderate
233.5Moderate
243.4Moderate
253.4Moderate
263.3Moderate
273.3Moderate
283.3Moderate
293.2Moderate
303.2Moderate
313.1Moderate
Planning a trip in August

Is August a good time to visit Letterkenny?

Our two travel scores rate August for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

4.3
Sightseeing
1st-best month of the year
Beach & pool
never really warm enough

August is a reasonable time to visit Letterkenny for sightseeing.

What to pack for Letterkenny in August

From August's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In August, Letterkenny sees daytime highs around 17°C and nights near 12°C. Pack rain gear. About 18 days see rain.

rain gear

Sea temperature near Letterkenny in August

The nearest coast averages about 15°C in August — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 45 km away) is warmest in August at about 15°C and coldest in February near 9°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

10°15°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan9Bracing
Feb9Bracing
Mar9Bracing
Apr9Bracing
May11Bracing
Jun13Bracing
Jul15Bracing
Aug15Cool
Sep15Bracing
Oct13Bracing
Nov12Bracing
Dec10Bracing

UV index in Letterkenny in August

LowModerateHighVery highExtreme

Clear-sky midday UV in August peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Letterkenny peaks around May 24 at about 5 (high) — a little sun protection helps at midday. It bottoms out near January 1 at about 0 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowMay 24UV 5Jan 1UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Moderate
Apr3Moderate
May5High
Jun5High
Jul5High
Aug5Moderate
Sep3Moderate
Oct2Low
Nov1Low
Dec0Low
Location & terrain

Where is Letterkenny?

Letterkenny sits at 55.0°N, 7.7°W, 8 m above sea level, in Ireland. The nearest listed city is Londonderry County Borough, 28 km away.

Londonderry County BoroughDerryOmaghColeraineSligoBallymenaAntrimPortadown

Topography around Letterkenny

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Letterkenny.

Within 3 km, the terrain around Letterkenny has only modest variations in elevation — a maximum elevation change of 199 m around an average of 73 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 452 m; within 80 km, large variations in elevation — a maximum elevation change of 706 m.

The land around Letterkenny is covered by grassland (60%) and trees (25%) within 3 km, grassland (72%) and trees (20%) within 16 km, and grassland (53%) and water (38%) within 80 km.

3 km
199 m
16 km
452 m
80 km
706 m
treesgrasslandcroplandartificial surfaceswater
August weather nearby: Londonderry County Borough 28 km · Derry 28 km · Omagh 48 km · Coleraine 71 km · Sligo 89 km · Ballymena 94 km · Antrim 101 km · Portadown 101 km

Ireland travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type G
230 V · 50 Hz
Prices
≈ 85% of US
price level, 2025
GDP per capita
$131,592
2025
Happiness
6.9 / 10
World Happiness, 2025
Safe drinking water
96%
of population, 2024
Homicide rate
0.7
per 100k, 2023
Road deaths
3.1
per 100k/yr, 2019
Income group
High
World Bank
Religion
Roman Catholic 69%none 15%Protestant 4%Orthodox 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Letterkenny (54.95°, -7.7333°, elevation 8 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).