AI-generatedCaernarfon at a glance
- Best time
- May – Sep
- Warmest month
- Jul · 19°
- Warmest sea
- Aug · 15.4°
- Sunshine a year
- 1,680 h
- Rain a year
- 967 mm
- Climate
- Maritime
- Time zone
- UTC+0 / UTC+1
- Elevation
- 33 m
Climate in Caernarfon
Caernarfon has a maritime climate with moderate summers and cool, often grey winters. July is the warmest month with average highs of 19 °C, while January is the coolest at 9 °C. With around 1,680 hours of sunshine a year, Caernarfon is moderately sunny; May is the sunniest month with 7.5 hours a day.
Holiday weather through the year
Best time to visit Caernarfon
The best time to visit Caernarfon is from May to September. The sea stays too cool for a classic beach holiday: even in August it only reaches 15.4 °C. The wettest month is November with 108 mm of precipitation.
Caernarfon through the seasons
How the weather changes over the seasons, with averages for each.
Caernarfon in spring
Mar – May
Fair
- 10–15 °C by day
- Sea 9 °C
- 5.9 h of sun a day
- 40 rainy days in all
Caernarfon in summer
Jun – Aug
Good
- 17–19 °C by day
- Sea 14 °C
- 6.7 h of sun a day
- 40 rainy days in all
Caernarfon in autumn
Sep – Nov
Fair
- 11–17 °C by day
- Sea 14 °C
- 3.5 h of sun a day
- 45 rainy days in all
Caernarfon in winter
Dec – Feb
Poor
- 9 °C by day
- Sea 10 °C
- 2.2 h of sun a day
- 45 rainy days in all
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
Rainy season or more than 12 rainy days
Find your perfect month
Tell us what you like and we rate every month in Caernarfon for you.
Your best months: June – August
Based on the climate averages; tap a month to see its details.
Weather in October
Weather in October
Holiday weather in October
Fair
Best time to visit: May – September
Where to go in OctoberSea temperature in October
Keep in mindFrequent rain
A typical day in October
- Morning, 08:00: about 10°
- Midday, 13:00: about 14°
- Afternoon, 16:00: about 14°
- Evening, 20:00: about 12°
- Night, 23:00: about 11°
07:4118:24
Cool evenings: pack a jumper or a jacket.
Estimated from the average high and low: coolest around sunrise, warmest in mid-afternoon.
Light for photos in October
- Golden hour
- Morning 07:20–08:29 · evening 17:36–18:45
- Blue hour
- Morning 07:06–07:20 · evening 18:45–18:59
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.
October in Caernarfon compared with home
Loading the climate at home …
Early or late October?
In October, daytime highs fall from about 16° at the start of the month to 13° at the end. The sea cools from 15° to 14°. The days get 2.0 h shorter.
| October | 1 Oct | 31 Oct |
|---|---|---|
| Daytime high | 16° | 13° |
| Night-time low | 10° | 8° |
| Sea | 15° | 14° |
| Daylight | 11.7 h | 9.7 h |
What is the weather like in Caernarfon in October?
In October, Caernarfon is cool: daytime highs average 14 °C, and nights cool down to about 9 °C. The sea averages 14.4 °C – swimming is only for the hardy. The sun is scarce, with only about 3.5 hours a day. It rains often – on about 16 days, adding up to 106 mm. It is often windy: on a typical day the wind peaks at around 29 km/h. All in all, October is a so-so month for a holiday in Caernarfon.
More details for October
- Daylight
- 10 h 43 min07:41 – 18:24
- UV index
- 2 · lowclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or moreAll months
- Wind
- 29 km/haverage daily peakAll months
- Cloud cover
- 73 %on averageAll months
- Hot days
- 0 days30 °C or more
- Time zone
- UTC+1offset from UTC
How the score comes together
- Temperatureweight 50 %71 %
- Sunshineweight 20 %8 %
- Few rainy daysweight 30 %18 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Nature escape”.
What to pack in October
- A jumper for the evenings
- Rain jacket or umbrella
- Windproof jacket
Compare two months in Caernarfon
Pick two months to see how the weather differs. A tick marks the clearly better value; for temperatures it depends on your plans.
June has the better holiday weather in Caernarfon: score 76 against 43. In June, days are 3 °C warmer than in October. The sea is 2 °C cooler in June. June has 3 fewer rainy days. The sun shines 4 hours longer a day in June.
| Month | October | June |
|---|---|---|
| Holiday weather score | 43 | 76better |
| Daytime high | 14° | 17° |
| Night-time low | 9° | 11° |
| Sea | 14.4° | 12.5° |
| Sunshine | 3.5 h | 7.3 hbetter |
| Rainy days | 16 | 13better |
| Rainfall | 106 mm | 67 mmbetter |
Based on the climate averages 1996–2025.
Caernarfon month by month
The typical weather for every month at a glance.
9January9° · Sea 9° · 2.0 h
In January, Caernarfon is cold: daytime highs average 9 °C, and nights cool down to about 4 °C. The sea averages 9.4 °C – swimming is only for the hardy. The sun is scarce, with only about 2.0 hours a day. It rains often – on about 15 days, adding up to 88 mm. It is often windy: on a typical day the wind peaks at around 31 km/h. All in all, January is not an ideal month for a holiday in Caernarfon.
Caernarfon in January13February9° · Sea 9° · 3.0 h
In February, Caernarfon is cold: daytime highs average 9 °C, and nights cool down to about 4 °C. The sea averages 8.5 °C – swimming is only for the hardy. The sun is scarce, with only about 3.0 hours a day. Rain is frequent, with about 13 rainy days and 74 mm in total. It is often windy: on a typical day the wind peaks at around 31 km/h. All in all, February is not an ideal month for a holiday in Caernarfon.
Caernarfon in February24March10° · Sea 8° · 4.2 h
In March, Caernarfon is cold: daytime highs average 10 °C, and nights cool down to about 5 °C. The sea averages 8.3 °C – swimming is only for the hardy. Expect around 4.2 hours of sunshine a day. Rain is frequent, with about 14 rainy days and 69 mm in total. All in all, March is not an ideal month for a holiday in Caernarfon.
Caernarfon in March44April12° · Sea 9° · 6.1 h
In April, Caernarfon is cool: daytime highs average 12 °C, and nights cool down to about 6 °C. The sea averages 9.1 °C – swimming is only for the hardy. Expect around 6.1 hours of sunshine a day. Rain is frequent, with about 13 rainy days and 63 mm in total. All in all, April is a so-so month for a holiday in Caernarfon.
Caernarfon in April65May15° · Sea 11° · 7.5 h
In May, Caernarfon is cool: daytime highs average 15 °C, and nights cool down to about 9 °C. The sea averages 10.6 °C – swimming is only for the hardy. The sun shines for around 7.5 hours a day. Rain is frequent, with about 13 rainy days and 64 mm in total. All in all, May is a good month for a holiday in Caernarfon.
Caernarfon in May76June17° · Sea 13° · 7.3 h
In June, Caernarfon is mild: daytime highs average 17 °C, and nights cool down to about 11 °C. The sea averages 12.5 °C – swimming is only for the hardy. The sun shines for around 7.3 hours a day. Rain is frequent, with about 13 rainy days and 67 mm in total. All in all, June is a good month for a holiday in Caernarfon.
Caernarfon in June71July19° · Sea 14° · 6.6 h
In July, Caernarfon is mild: daytime highs average 19 °C, and nights cool down to about 13 °C. The sea averages 14.2 °C – swimming is only for the hardy. The sun shines for around 6.6 hours a day. Rain is frequent, with about 14 rainy days and 66 mm in total. All in all, July is a good month for a holiday in Caernarfon.
Caernarfon in July70August19° · Sea 15° · 6.1 h
In August, Caernarfon is mild: daytime highs average 19 °C, and nights cool down to about 13 °C. The sea averages 15.4 °C – swimming is only for the hardy. Expect around 6.1 hours of sunshine a day. Rain is frequent, with about 14 rainy days and 75 mm in total. All in all, August is a good month for a holiday in Caernarfon.
Caernarfon in August67September17° · Sea 15° · 5.0 h
In September, Caernarfon is mild: daytime highs average 17 °C, and nights cool down to about 12 °C. The sea averages 15.4 °C – swimming is only for the hardy. Expect around 5.0 hours of sunshine a day. Rain is frequent, with about 13 rainy days and 83 mm in total. All in all, September is a good month for a holiday in Caernarfon.
Caernarfon in September43October14° · Sea 14° · 3.5 h
In October, Caernarfon is cool: daytime highs average 14 °C, and nights cool down to about 9 °C. The sea averages 14.4 °C – swimming is only for the hardy. The sun is scarce, with only about 3.5 hours a day. It rains often – on about 16 days, adding up to 106 mm. It is often windy: on a typical day the wind peaks at around 29 km/h. All in all, October is a so-so month for a holiday in Caernarfon.
Caernarfon in October22November11° · Sea 13° · 2.1 h
In November, Caernarfon is cool: daytime highs average 11 °C, and nights cool down to about 7 °C. The sea averages 12.7 °C – swimming is only for the hardy. The sun is scarce, with only about 2.1 hours a day. It rains often – on about 17 days, adding up to 108 mm. It is often windy: on a typical day the wind peaks at around 30 km/h. All in all, November is not an ideal month for a holiday in Caernarfon.
Caernarfon in November11December9° · Sea 11° · 1.6 h
In December, Caernarfon is cold: daytime highs average 9 °C, and nights cool down to about 5 °C. The sea averages 10.9 °C – swimming is only for the hardy. The sun is scarce, with only about 1.6 hours a day. It rains often – on about 16 days, adding up to 106 mm. It is often windy: on a typical day the wind peaks at around 31 km/h. All in all, December is not an ideal month for a holiday in Caernarfon.
Caernarfon in DecemberClimate in detail
Climate through the year
Long-term monthly averages. Tap a month to see its details.
Nights and sleep in Caernarfon
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 9°. A duvet at night and a jumper for the evening.
The coolest nights are in February (4°), the warmest in August (13°). 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 | 9 | 9° | 4° | 9.4° | 2.0 h | 15 | 88 |
| FebruaryFeb | 13 | 9° | 4° | 8.5° | 3.0 h | 13 | 74 |
| MarchMar | 24 | 10° | 5° | 8.3° | 4.2 h | 14 | 69 |
| AprilApr | 44 | 12° | 6° | 9.1° | 6.1 h | 13 | 63 |
| MayMay | 65 | 15° | 9° | 10.6° | 7.5 h | 13 | 64 |
| JuneJun | 76 | 17° | 11° | 12.5° | 7.3 h | 13 | 67 |
| JulyJul | 71 | 19° | 13° | 14.2° | 6.6 h | 14 | 66 |
| AugustAug | 70 | 19° | 13° | 15.4° | 6.1 h | 14 | 75 |
| SeptemberSep | 67 | 17° | 12° | 15.4° | 5.0 h | 13 | 83 |
| OctoberOct | 43 | 14° | 9° | 14.4° | 3.5 h | 16 | 106 |
| NovemberNov | 22 | 11° | 7° | 12.7° | 2.1 h | 17 | 108 |
| DecemberDec | 11 | 9° | 5° | 10.9° | 1.6 h | 16 | 106 |
Climate averages 1996–2025 (sunshine partly WMO station normals 1991–2020), 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
53.14° N, 4.27° W · 33 m · Europe/London
Sea temperature in Caernarfon
Monthly sea surface temperature with the range of cooler and warmer years.
8 in 10 years: 14.0 – 15.0 °C
Swimming season: Always below 20 °C
- cold
- fresh
- refreshing
- pleasant
- warm
- very warm
The sea temperature in Caernarfon ranges from 8.3 °C in March to 15.4 °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 November to January 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 14.9 and 16.1 °C.
| Month | Average | Cool year | Warm year | Feels |
|---|---|---|---|---|
| JanuaryJan | 9.4° | 8.5° | 10.2° | cold |
| FebruaryFeb | 8.5° | 7.7° | 9.2° | cold |
| MarchMar | 8.3° | 7.5° | 9.0° | cold |
| AprilApr | 9.1° | 8.3° | 9.9° | cold |
| MayMay | 10.6° | 10.0° | 11.7° | cold |
| JuneJun | 12.5° | 11.9° | 12.9° | cold |
| JulyJul | 14.2° | 13.7° | 14.5° | cold |
| AugustAug | 15.4° | 14.9° | 16.1° | cold |
| SeptemberSep | 15.4° | 14.8° | 16.0° | cold |
| OctoberOct | 14.4° | 14.0° | 15.0° | cold |
| NovemberNov | 12.7° | 12.2° | 13.2° | cold |
| DecemberDec | 10.9° | 10.4° | 11.4° | cold |
Sunshine hours in Caernarfon
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 3.5 of 10.7 hours of daylight in Caernarfon, 33 % of the daylight hours.
Sunshine hours: measured at the weather station 22 km away, averages 1991–2020 (WMO climate normals). Daylight is the time from sunrise to sunset on the 15th of the month.
Rain in Caernarfon: 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, Caernarfon has about 16 rainy days with 106 mm of rain in total.
UV index in Caernarfon
How strong the sun is at noon, month by month, and how quickly unprotected skin burns.
- Clear-sky UV in October
- 2 · lowLittle protection needed; sunglasses on bright days.
The sun is strongest in June (UV 7).
Minutes until sunburn in October
- Very fair skin
- about 80 min
- Fair skin
- about 100 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 the time, 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.
Wind and clouds in Caernarfon
How breezy and how cloudy Caernarfon 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 Caernarfon typically peaks at 29 km/h during the day: Beaufort 5, fresh 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, and here it is that strong all year.
Clouds
Average share of the sky covered by cloud, day and night.
In October, cloud covers on average 73 % of the sky over Caernarfon: mostly cloudy, with about 3.5 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.
Planning a trip to Caernarfon
Weather for your travel dates
Pick your arrival and length of stay, and we sum up the weather to expect.
Caernarfon 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.
Caernarfon has its best school-holiday weather during the summer holidays (score 70) and its weakest during the Christmas holidays (score 10).
- 38
Easter holidays
Mar – Apr
Poor
- 12 °C by day
- Sea 9 °C
- 5.5 h of sun a day
- 13 rainy days a month
Keep in mind: Frequent rain
- 67
May half-term
May – Jun
Good
- 16 °C by day
- Sea 11 °C
- 7.5 h of sun a day
- 13 rainy days a month
Keep in mind: Frequent rain
- 70
Summer holidays
Jul – Aug
GoodBest holidays
- 19 °C by day
- Sea 15 °C
- 6.3 h of sun a day
- 14 rainy days a month
Keep in mind: Frequent rain
- 43
October half-term
Oct
Fair
- 14 °C by day
- Sea 14 °C
- 3.5 h of sun a day
- 16 rainy days a month
Keep in mind: Frequent rain
- 10
Christmas holidays
Dec – Jan
Poor
- 9 °C by day
- Sea 10 °C
- 1.8 h of sun a day
- 16 rainy days a month
Keep in mind: Frequent rain
Based on the climate averages 1996–2025.
Getting there
Flying from
- Nonstop flight
- Short trip – train or car is often quicker
- Distance
- 320 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.
Compare & alternatives
Caernarfon compared
Put Caernarfon side by side with another destination.
Caernarfon vs Llanfairpwllgwyngyll
In October the holiday weather in Caernarfon and Llanfairpwllgwyngyll is about equally good (score 43 vs 42). During the day it is about as warm in Llanfairpwllgwyngyll as in Caernarfon. The sea is about equally warm.
| in October | Caernarfon | Llanfairpwllgwyngyll |
|---|---|---|
| Holiday weather score | 43 | 42 |
| Daytime high | 14° | 14° |
| Sea | 14° | 14° |
| Sunshine | 4 h | 4 h |
| Rainy days | 16 | 16 |
| Best time | May – Sep | May – Sep |
Through the year
United Kingdom in October: the best places
In October, Caernarfon ranks 5 among the 31 nearest destinations in this country.
- Hereford15°47
- 2Stourbridge15°46
- 3Shrewsbury14°44
- 4Wolverhampton14°44
- 5CaernarfonThis page14°14°43
- 6Holyhead15°14°43
- 7Wrexham14°43
- 8Llanfairpwllgwyngyll14°14°42
Near Caernarfon
Other destinations close by.
Places with a climate like Caernarfon
Destinations whose weather through the year is closest to Caernarfon's – good alternatives.
Frequently asked questions about Caernarfon
When is the best time to visit Caernarfon?
The best time to visit Caernarfon is from May to September. That is when the holiday weather score, which combines temperature, sea, sunshine and rain, is highest.
How warm is the sea in Caernarfon?
The sea temperature in Caernarfon ranges from 8.3 °C in March to 15.4 °C in August. Even at its warmest the sea stays below 20 °C, so swimming is bracing at best.
Can you swim in Caernarfon in October?
Only if you don't mind cold water: in October the sea averages just 14.4 °C. Comfortable swimming temperatures are not reached at any time of year.
What is the warmest month in Caernarfon?
July is the warmest month, with average highs of 19 °C and nights around 13 °C. January is the coolest month at 9 °C.
When does it rain most in Caernarfon?
The wettest month is November with 108 mm of precipitation. The driest month is April with 63 mm.
How many hours of sunshine does Caernarfon get?
Caernarfon gets around 1,680 hours of sunshine a year. The sunniest month is May with 7.5 hours a day; in December there are 1.6 hours a day.
What time zone is Caernarfon in?
Caernarfon is on UTC+0 in January and UTC+1 in July.
Which school holidays are best for Caernarfon?
Caernarfon has its best school-holiday weather during the summer holidays (score 70) and its weakest during the Christmas holidays (score 10). Holiday ratings (0–100): Easter holidays 38, May half-term 67, summer holidays 70, October half-term 43, Christmas holidays 10.