Arklow climate — normals and trends
Arklow (Ireland) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 9.8 °C and it receives 834 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (15.2 °C on average) and the coldest is January (5.2 °C). Rainfall peaks in October.
Arklow averages 14 frost days, 0 hot days (≥ 30 °C) and 150 rainy days per year.
Arklow has warmed by +0.8 °C between 1940 and 2025, or +0.09 °C per decade. This trend is statistically significant.
The number of frost days there went from about 20 to 8 per year over the period.
The hottest day of the period reached 26.5 °C (on 13 July 1983) and the coldest -9.2 °C (on 3 December 2010).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
ArklowLeinster
- coords
- 52.79°, -6.15°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
9.8°C
Average daily high
12.4°C
Average daily low
7.2°C
Annual rainfall
834mm
Sunshine / day
8.1h
Mean relative humidity
82%
Average peak wind
23.0km/h
Seasonal range
10.0°C
Frost days (< 0 °C)
14 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
150 d/yr
Annual snowfall
11.1 cm
Average feels-like high
9.6 °C
Average feels-like low
3.9 °C
Average peak gust
45.8 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
11.0 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+0.8 °C
since 1940
+0.1 °C per decade · r² = 0.21 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
26.5 °C
13 July 1983
Coldest day
-9.2 °C
3 December 2010
Wettest day
91 mm
29 June 1986
Windiest day
66.2 km/h
23 April 1947
Strongest gust
138.2 km/h
23 April 1947
Hottest feels-like
29.5 °C
13 July 1983
Coldest feels-like
-13.7 °C
3 December 2010
Snowiest day
25.1 cm
8 January 1982
Sunniest day
16.7 h
20 June 1944
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 7.3 °C | 0.0 °C | 102 mm | +25 mm |
| Feb | 8.5 °C | +1.0 °C | 82 mm | +21 mm |
| Mar | 11.0 °C | +1.9 °C | 19 mm | -44 mm |
| Apr | 13.2 °C | +2.1 °C | 94 mm | +35 mm |
| May | 16.1 °C | +2.3 °C | 36 mm | -30 mm |
| Jun | 17.8 °C | +1.2 °C | 71 mm | +10 mm |
| Jul | 19.7 °C | +1.5 °C | 95 mm | +32 mm |
| Aug | 19.4 °C | +1.3 °C | 28 mm | -42 mm |
| Sep | 16.1 °C | 0.0 °C | 114 mm | +43 mm |
| Oct | 13.4 °C | +0.3 °C | 103 mm | +18 mm |
| Nov | 10.9 °C | +1.1 °C | 119 mm | +43 mm |
| Dec | 9.3 °C | +1.2 °C | 111 mm | +29 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Arklow?
Arklow has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 9.8 °C and it receives 834 mm of precipitation per year.
What is the hottest day ever recorded in Arklow?
The hottest day measured in Arklow between 1940 and 2025 was 13 July 1983, reaching 26.5 °C.
What is the coldest day in Arklow?
The coldest day measured in Arklow between 1940 and 2025 was 3 December 2010, at -9.2 °C.
Does it snow in Arklow?
Yes. Arklow gets on average 11.1 cm of snow per year and has around 14 frost days.
Has the climate of Arklow warmed?
Yes: Arklow warmed by +0.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Arklow?
The wettest day measured in Arklow between 1940 and 2025 was 29 June 1986, with 91 mm of rain in 24 hours.
What was the windiest day in Arklow?
The windiest day measured in Arklow between 1940 and 2025 was 23 April 1947, with winds reaching 66.2 km/h.
What is the warmest month in Arklow?
The warmest month in Arklow is July (15.2 °C on average); the coldest is January (5.2 °C).
How much does it rain in Arklow?
Arklow receives on average 834 mm of precipitation per year, spread over about 150 rainy days.
Is it sunny in Arklow?
Arklow gets on average 8.1 hours of sunshine per day, roughly 2,957 hours per year over 1940-2025.
What is the biggest single-day snowfall in Arklow?
The heaviest 24-hour snowfall measured in Arklow between 1940 and 2025 was 8 January 1982, with 25.1 cm.
Are there tropical nights in Arklow?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Arklow.
What was the most extreme apparent temperature in Arklow?
In Arklow, between 1940 and 2025, the highest apparent temperature reached 29.5 °C on 13 July 1983, and the lowest was -13.7 °C on 3 December 2010.
Compare Arklow with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Arklow