Annual mean 10°C · wettest around December · prevailing wind SW
Warmest
18.2 °C
Coldest
6.1 °C
Wettest
36%
Windiest
8.6 m/s
Prevailing
SW
6.5 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
never good
never good
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Caernarfon over the whole year is 10°C. July is the hottest month, with highs of about 18°C; March is the coldest, with lows of about 5°C. The rainy (wet) season in Caernarfon runs from September to March, peaking in December with a 35% chance of rain on a given day. The dry season is April to August; May is the driest month, at 17%. Winds in Caernarfon are highest in February, averaging 7.3 m/s (26 km/h), and lightest in May, at 4.8 m/s (17 km/h). The prevailing wind is from the SW. The clearest skies in Caernarfon come in May, when the sky is typically 59% covered; December is the cloudiest month, at 76%.
Month by month Caernarfon climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
6°C
5°C
0°C
29%
73%
6.5 m/s
0
0
7
February
7°C
5°C
0°C
31%
70%
7.3 m/s
0
0
10
March
9°C
5°C
2°C
28%
69%
6.1 m/s
1
0
20
April
11°C
6°C
6°C
19%
63%
4.9 m/s
5
0
42
May
14°C
10°C
10°C
17%
59%
4.8 m/s
18
0
68
June
16°C
12°C
13°C
21%
65%
5.2 m/s
34
2
73
July
18°C
14°C
14°C
22%
69%
4.9 m/s
45
4
78
August
18°C
14°C
14°C
23%
66%
5.5 m/s
42
3
76
September
16°C
12°C
12°C
28%
68%
5.3 m/s
29
2
72
October
13°C
10°C
8°C
29%
70%
6.1 m/s
4
0
56
November
9°C
8°C
4°C
31%
73%
6.0 m/s
0
0
29
December
8°C
6°C
2°C
35%
76%
6.8 m/s
0
0
12
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Caernarfon weather by season
Year round, Caernarfon has days of about 6°C at their warmest in January, its coolest month, and 18°C in July, its warmest; the coolest hours of the day run from 5°C to 14°C through the year, and the average temperature over the year is 10°C around the clock. Rain is most likely around December and least likely around May. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Caernarfon weather in winterDecember to February
High 7°CLow 6°CRain 32%
Winter in Caernarfon has typical daily highs of about 7°C and lows of about 6°C, with a 32% chance of rain on a given day.
Caernarfon weather in springMarch to May
High 11°CLow 7°CRain 21%
Spring in Caernarfon has typical daily highs of about 11°C and lows of about 7°C, with a 21% chance of rain on a given day.
Caernarfon weather in summerJune to August
High 17°CLow 13°CRain 22%
Summer in Caernarfon has typical daily highs of about 17°C and lows of about 13°C, with a 22% chance of rain on a given day.
Caernarfon weather in autumnSeptember to November
High 13°CLow 10°CRain 30%
Autumn in Caernarfon has typical daily highs of about 13°C and lows of about 10°C, with a 30% chance of rain on a given day.
When is the rainy season in Caernarfon?
The rainy (wet) season in Caernarfon runs from September to March, peaking in December with a 35% chance of rain on a given day. The dry season is April to August; May is the driest month, at 17%.
What time of year is Caernarfon windiest?
Winds in Caernarfon are highest in February, averaging 7.3 m/s (26 km/h), and lightest in May, at 4.8 m/s (17 km/h). The prevailing wind is from the SW.
What is the average temperature in Caernarfon year round?
The average temperature in Caernarfon over the whole year is 10°C. July is the hottest month, with highs of about 18°C; March is the coldest, with lows of about 5°C.