Ballymun climate — normals and trends
Ballymun (Ireland) has a temperate oceanic climate (Cfb) under the Köppen-Geiger classification. Its mean annual temperature is 10.2 °C and it receives 753 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 (15.7 °C on average) and the coldest is January (5.5 °C). Rainfall peaks in August.
Ballymun averages 11 frost days, 0 hot days (≥ 30 °C) and 146 rainy days per year.
Ballymun 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 16 to 6 per year over the period.
The hottest day of the period reached 28.3 °C (on 18 July 2022) and the coldest -9.5 °C (on 12 January 1982).
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
BallymunLeinster
- coords
- 53.40°, -6.27°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
10.2°C
Average daily high
12.8°C
Average daily low
7.7°C
Annual rainfall
753mm
Sunshine / day
7.7h
Mean relative humidity
81%
Average peak wind
22.6km/h
Seasonal range
10.2°C
Frost days (< 0 °C)
11 d/yr
Hot days (≥ 30 °C)
0 d/yr
Rainy days (≥ 1 mm)
146 d/yr
Annual snowfall
9.2 cm
Average feels-like high
10.0 °C
Average feels-like low
4.4 °C
Average peak gust
43.4 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
10.2 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+0.8 °C
since 1940
+0.1 °C per decade · r² = 0.20 · 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
28.3 °C
18 July 2022
Coldest day
-9.5 °C
12 January 1982
Wettest day
55 mm
25 August 1986
Windiest day
65.3 km/h
24 December 1997
Strongest gust
145.8 km/h
24 December 1997
Hottest feels-like
30.7 °C
13 July 1983
Coldest feels-like
-14.0 °C
25 December 2010
Snowiest day
24.2 cm
8 December 1954
Sunniest day
16.8 h
20 June 1940
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 | 7.5 °C | -0.1 °C | 66 mm | +1 mm |
| Feb | 9.0 °C | +1.1 °C | 59 mm | +7 mm |
| Mar | 11.4 °C | +1.8 °C | 12 mm | -42 mm |
| Apr | 14.0 °C | +2.4 °C | 105 mm | +50 mm |
| May | 16.1 °C | +1.8 °C | 39 mm | -23 mm |
| Jun | 18.5 °C | +1.4 °C | 85 mm | +25 mm |
| Jul | 20.1 °C | +1.4 °C | 87 mm | +21 mm |
| Aug | 19.6 °C | +1.1 °C | 33 mm | -37 mm |
| Sep | 16.4 °C | -0.1 °C | 102 mm | +38 mm |
| Oct | 13.7 °C | +0.2 °C | 87 mm | +18 mm |
| Nov | 11.1 °C | +1.0 °C | 126 mm | +58 mm |
| Dec | 9.6 °C | +1.3 °C | 71 mm | +2 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 Ballymun?
Ballymun has a temperate oceanic climate (Köppen Cfb). Over 1940-2025, the average annual temperature is 10.2 °C and it receives 753 mm of precipitation per year.
What is the hottest day ever recorded in Ballymun?
The hottest day measured in Ballymun between 1940 and 2025 was 18 July 2022, reaching 28.3 °C.
What is the coldest day in Ballymun?
The coldest day measured in Ballymun between 1940 and 2025 was 12 January 1982, at -9.5 °C.
Does it snow in Ballymun?
Yes. Ballymun gets on average 9.2 cm of snow per year and has around 11 frost days.
Has the climate of Ballymun warmed?
Yes: Ballymun warmed by +0.8 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Ballymun?
The wettest day measured in Ballymun between 1940 and 2025 was 25 August 1986, with 55 mm of rain in 24 hours.
What was the windiest day in Ballymun?
The windiest day measured in Ballymun between 1940 and 2025 was 24 December 1997, with winds reaching 65.3 km/h.
What is the warmest month in Ballymun?
The warmest month in Ballymun is July (15.7 °C on average); the coldest is January (5.5 °C).
How much does it rain in Ballymun?
Ballymun receives on average 753 mm of precipitation per year, spread over about 146 rainy days.
Is it sunny in Ballymun?
Ballymun gets on average 7.7 hours of sunshine per day, roughly 2,811 hours per year over 1940-2025.
What is the biggest single-day snowfall in Ballymun?
The heaviest 24-hour snowfall measured in Ballymun between 1940 and 2025 was 8 December 1954, with 24.2 cm.
Are there tropical nights in Ballymun?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Ballymun.
What was the most extreme apparent temperature in Ballymun?
In Ballymun, between 1940 and 2025, the highest apparent temperature reached 30.7 °C on 13 July 1983, and the lowest was -14.0 °C on 25 December 2010.
Compare Ballymun with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Ballymun