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Climate in Rathcoole · Met Éireann 1991–2020 averages

Few Irish towns have colder winter nights than Rathcoole

Expect July afternoons of about 19.6°C. In July, afternoons here are cooler than in 77% of Irish towns. Decade by decade the climate has edged up, 0.2°C above 1981–2010. Long walks are most pleasant from June to September, when afternoons reach 17–20°C.

July afternoons: cooler than 77% of Irish towns
January nights: colder than 98% of Irish towns
Rain a year: drier than 60% of Irish towns

Met Éireann 1991–2020 averages for the town’s own square kilometre.

A year in Rathcoole at a glance

Each month’s typical high and low, in °C.

Jan8°C2°C
Feb8°C2°CColdest nights
Mar10°C3°C
Apr12°C4°CLast frost ~26 Apr
May15°C7°C
Jun18°C9°C
Jul20°C11°CWarmest
Aug19°C11°C
Sep17°C9°C
Oct14°C6°C
Nov now10°C4°CWettestFirst frost ~2 Nov
Dec8°C2°C

What stands out about Rathcoole’s climate

Compared with Irish towns, with its place among towns and neighbourhoods of 2,500+ in County Dublin beside it.

A normal year

What a year in Rathcoole feels like

Typical highs and lows by season and by month, from Met Éireann’s 1991–2020 averages.

Winter
8°C / 2°C
223 mm of rain
Spring
13°C / 4°C
179 mm of rain
Summer
19°C / 10°C
212 mm of rain
Autumn
14°C / 6°C
256 mm of rain, the wettest season
Best months to be outsideJunJulAugSepHighs of 17–27°C and nights of 8°C or more
Frost & warm days

36 frosts and 3 days of 25°C a year

Ground frosts, when the grass drops below 0°C, come on about 84 nights a year. Air frosts come mostly from October to April, most of all in February (about 7).

36
Air frosts a year (below 0°C)
84
Ground frosts a year (grass below 0°C)
3
Days of 25°C or more

Air frosts by month

Average nights below 0°C

7.2
JFMAMJJASOND

Ground frosts by month

Average nights with the grass below 0°C

14
JFMAMJJASOND

Counted from Casement’s daily readings, 1991–2020, 3.8 km north-east of Rathcoole: Met Éireann publishes these for its stations only.

Rain

About 869 mm of rain a year

November is the wettest month and March the driest. 8th wettest of 116 towns and neighbourhoods of 2,500+ in County Dublin. The wettest month brings about 1.6 times the rain of the driest. Casement records 1 mm or more on about 136 days a year, and 10 mm on about 18.

869 mm
Rain a year
Drier than 60% of Irish towns
94 mm
November, the wettest month
58 mm
March, the driest month
1,397 hrs
Hours of sunshine a year

Rain by month

Millimetres

94 mm
JFMAMJJASOND

Sunshine by month

Hours, at Casement

190 h
JFMAMJJASOND
Heating

Heating a home in Rathcoole

84% of a year’s heating need falls between October and April. Months averaging under 10°C: October to April.

2,164 heating degree days (below 15.5°C)a year, 1991–2020

Degree days add up how far each day’s mean temperature falls below 15.5°C over a year.

Living here

Living with Rathcoole’s climate

What the averages mean for a garden, a free afternoon and a bad-weather day.

The garden window

In half of years the last air frost at Casement comes by 26 April and the first by 2 November: about 190 frost-free days in between.

Get outside

Highs of 17–27°C with lows of 8°C or more: Jun, Jul, Aug and Sep.

Parks & trails →
Storms and extremes

Averages smooth over storms, floods and heatwaves; Rathcoole’s hazards page covers the risks.

Flood & hazards →
Weather station

Met Éireann’s nearest station: Casement

Casement is 3.8 km north-east of Rathcoole, the nearest of the 25 synoptic stations where Met Éireann records the weather around the clock. The station stands 91 m above sea level; Rathcoole’s centre, 118 m.

MonthHighLowRainAir frostsSun (hours)
January8.2°C2.4°C65 mm6.754
February8.5°C2.1°C55 mm7.275
March10.3°C2.8°C49 mm5.7107
April12.6°C4.1°C52 mm3.1157
May15.4°C6.6°C56 mm0.8190
June18.0°C9.2°C66 mm0.0167
July19.7°C11.2°C60 mm0.0153
August19.4°C10.9°C71 mm0.0153
September17.2°C9.0°C61 mm0.1125
October13.7°C6.7°C82 mm1.3102
November10.4°C4.3°C82 mm4.067
December8.4°C2.6°C76 mm7.248
Year13.5°C6.0°C774 mm361,397

The table is Casement’s own record, averaged over 1991–2020 from its daily readings (ours, not a Met Éireann table). The temperatures and rain elsewhere on this page are Met Éireann’s 1 km grid at Rathcoole itself; the frosts, sunshine and degree days are this station’s.

Compared with other towns

How Rathcoole compares

Against the 321 Irish towns and city neighbourhoods of 2,500 or more, each read from Met Éireann’s grid at its own centre, and its place among towns and neighbourhoods of 2,500+ in County Dublin.

July afternoons19.6°C
RathcooleMedian Irish town
18°C19°C20°C21°C
Cooler than 77% of Irish towns99th warmest of 116 towns and neighbourhoods of 2,500+ in County Dublin
January nights1.7°C
RathcooleMedian Irish town
1°C2°C3°C4°C
Colder than 98% of Irish towns116th mildest of 116 towns and neighbourhoods of 2,500+ in County Dublin
Rain a year869 mm
RathcooleMedian Irish town
4006008001,0001,200
Drier than 60% of Irish towns8th wettest of 116 towns and neighbourhoods of 2,500+ in County Dublin
Then and now

Warmer than it used to be

Rathcoole’s 1991–2020 average is 0.2°C warmer than 1981–2010’s. The biggest change is in February (+0.3°C).

+0.2°C1991–2020 vs 1981–2010

A year’s rain is 869 mm, up 2% from 850 mm.

Winter+0.2°Cnow 5°C, was 5°C
Spring+0.2°Cnow 9°C, was 8°C
Summer+0.2°Cnow 15°C, was 15°C
Autumn+0.2°Cnow 10°C, was 10°C

Change by month

JanFebMarAprMayJunJulAugSepOctNovDec

The two periods share 1991–2010, so the gap is a decade’s step, not the change between two separate 30-year periods.

Next door

Rathcoole and its neighbours

Every town next door is within half a degree of Rathcoole in January and July. Choose a measure to recolour the map; tap a town for its climate.

Saggart: January low 1.9°C, July high 19.6°CNewcastle: January low 1.9°C, July high 19.8°CJobstown: January low 2.0°C, July high 19.6°CFettercairn: January low 2.1°C, July high 19.7°CDeansrath: January low 2.3°C, July high 20.0°CTallaght: January low 2.2°C, July high 19.7°CRathcoole: January low 1.7°C, July high 19.6°CRathcooleSaggartNewcastleJobstownFettercairnDeansrathTallaght
ColderMilder1.7°C to 2.3°C
Rathcoole1.7°C
Saggart1.9°C about the same
Newcastle1.9°C about the same
Jobstown2.0°C about the same
Fettercairn2.1°C about the same
Tallaght2.2°C +0.5°C
Deansrath2.3°C +0.6°C

The towns next door, side by side

The nearest towns of 1,000+ within 19 km: a hill, a valley or the sea can make a real difference over a short distance.

TownJuly highJanuary lowRain a year
Rathcoole19.6°C1.7°C869 mm
Saggart 1.8 km19.6°C about the same1.9°C about the same855 mm
Newcastle 2.3 km19.8°C about the same1.9°C about the same825 mm
Jobstown 4.3 km19.6°C about the same2.0°C about the same854 mm
Fettercairn 4.7 km19.7°C about the same2.1°C about the same826 mm
Deansrath 6.4 km20.0°C about the same2.3°C 0.6°C milder791 mm
Tallaght 6.7 km19.7°C about the same2.2°C 0.5°C milder825 mm

Each town’s colour is Met Éireann’s 1 km grid at its own centre, so towns a few kilometres apart can differ.

Month by month

Rathcoole weather by month

Average daily high and low, mean temperature and rain, 1991–2020, for the town itself (Met Éireann’s 1 km grid).

MonthHighLowMeanRain
January7.7°C1.7°C4.7°C73 mm
February8.3°C1.6°C4.9°C64 mm
March10.1°C2.6°C6.4°C58 mm
April12.4°C4.1°C8.2°C60 mm
May15.3°C6.5°C10.9°C61 mm
June18.0°C9.2°C13.6°C68 mm
July19.6°C11.2°C15.4°C67 mm
August19.3°C10.8°C15.0°C76 mm
September17.0°C8.9°C12.9°C71 mm
October13.5°C6.3°C9.9°C90 mm
November10.1°C3.7°C6.9°C94 mm
December8.0°C2.0°C5.0°C86 mm
Year13.3°C5.7°C9.5°C869 mm
Year to year

How much a month can swing

December swings the most: over 30 years its average ranged from −0.5°C (2010) to 8.5°C (2015). July is the most reliable, staying within 3.7°C.

Coldest to warmest month in 30 yearsNormal
Sources

Where Rathcoole’s numbers come from

Averages over 30 years, not a forecast: the town’s own from Met Éireann’s grid, the frosts, sunshine and degree days from its nearest station.

  • Temperature and rain: Met Éireann’s 1991–2020 averages on its 1 km grid (Climatological Notes 22 and 23), read at the grid point nearest Rathcoole’s population centre (0.5 km away).
  • Weather station: the nearest of Met Éireann’s 25 synoptic stations, Casement, 3.8 km north-east, from Met Éireann’s station list.
  • Frosts, sunshine, degree days: Casement’s daily readings from Met Éireann (clidata.met.ie), 1991–2020, averaged by month: a month counts when 27 or more of its days were read (rain and sunshine: every day), and a figure needs 10 such years.
  • Then and now: Met Éireann’s 1981–2010 averages on the same 1 km grid, at the same point.
  • Altitudes: the town’s ground from the Copernicus GLO-30 surface model (a few metres high in built-up places), the station’s from Met Éireann.
  • Comparisons: every Irish town and city neighbourhood of 2,500 or more, read the same way; the five city totals are left out.
  • Not on this page: snow and wind. Met Éireann publishes neither on a grid; the frosts and sunshine here are its nearest station’s, not the town’s own.

Met Éireann 30-year averages · Met Éireann open data. Under Creative Commons Attribution 4.0 (CC BY 4.0).

Questions about Rathcoole’s climate

How warm does Rathcoole get in summer?

July is the warmest month, with average highs of 19.6°C.

How cold does Rathcoole get in winter?

The coldest nights come in February, averaging 1.6°C. At Casement, the nearest Met Éireann station, the air drops below 0°C on about 36 nights a year (1991–2020).

How much rain does Rathcoole get?

About 869 mm a year, less than 60% of Irish towns. November is the wettest month (94 mm) and March the driest (58 mm).

How sunny is it?

Casement, 3.8 km north-east, averages about 1,397 hours of sunshine a year (1991–2020, from its daily record). Met Éireann publishes no sunshine figure for the town itself.

Are these figures for Rathcoole itself?

Partly. The temperatures and rain are Met Éireann’s 1991–2020 averages on its 1 km grid, read at Rathcoole’s population centre; the frosts, degree days and year-to-year swings are those of Casement, 3.8 km north-east, the nearest of its synoptic stations.

Where do these figures come from?

Met Éireann’s 1991–2020 climate averages, published as maps of Ireland in 1 km squares (Climatological Notes 22 and 23); the page reads the square at Rathcoole’s population centre. They are 30-year averages, not a forecast.

Copyright Met Éireann. Source: www.met.ie. This data is published under a Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Met Éireann does not accept any liability whatsoever for any error or omission in the data, their availability, or for any loss or damage arising from their use. This material has been modified from the original: TownRatings reads the 1 km grid at each town’s population centre. Today’s forecast for Rathcoole →

Contains Central Statistics Office (CSO) data, Census 2022, and Tailte Éireann boundaries (CSO Urban Areas, Small Areas, local electoral areas, constituencies), under Creative Commons Attribution 4.0 (CC BY 4.0).