Winter nights in Rathnew are milder than in 75% of Irish towns
Sunny July days climb to about 19.7°C. Its July afternoons stay fresher than in 67% of Irish towns. Warming shows here too: 0.2°C more than in 1981–2010, led by February. Central heating does most of its work from November to April, in months below 10°C on average.
Met Éireann 1991–2020 averages for the town’s own square kilometre.
A year in Rathnew at a glance
Each month’s typical high and low, in °C.
What stands out about Rathnew’s climate
Compared with Irish towns, with its place among towns of 2,500+ in County Wicklow beside it.
What a year in Rathnew feels like
Typical highs and lows by season and by month, from Met Éireann’s 1991–2020 averages.
About 1,007 mm of rain a year
November is the wettest month and July the driest. 3rd wettest of 9 towns of 2,500+ in County Wicklow. The wettest month brings about 2.0 times the rain of the driest.
Rain by month
Millimetres
Living with Rathnew’s climate
What the averages mean for a garden, a free afternoon and a bad-weather day.
Highs of 17–27°C with lows of 8°C or more: Jun, Jul, Aug and Sep.
Parks & trails →Averages smooth over storms, floods and heatwaves; Rathnew’s hazards page covers the risks.
Flood & hazards →Met Éireann’s nearest station: Casement
Casement is 43 km north-west of Rathnew, the nearest of the 25 synoptic stations where Met Éireann records the weather around the clock. The station stands 91 m above sea level; Rathnew’s centre, 51 m.
| Month | High | Low | Rain | Air frosts | Sun (hours) |
|---|---|---|---|---|---|
| January | 8.2°C | 2.4°C | 65 mm | 6.7 | 54 |
| February | 8.5°C | 2.1°C | 55 mm | 7.2 | 75 |
| March | 10.3°C | 2.8°C | 49 mm | 5.7 | 107 |
| April | 12.6°C | 4.1°C | 52 mm | 3.1 | 157 |
| May | 15.4°C | 6.6°C | 56 mm | 0.8 | 190 |
| June | 18.0°C | 9.2°C | 66 mm | 0.0 | 167 |
| July | 19.7°C | 11.2°C | 60 mm | 0.0 | 153 |
| August | 19.4°C | 10.9°C | 71 mm | 0.0 | 153 |
| September | 17.2°C | 9.0°C | 61 mm | 0.1 | 125 |
| October | 13.7°C | 6.7°C | 82 mm | 1.3 | 102 |
| November | 10.4°C | 4.3°C | 82 mm | 4.0 | 67 |
| December | 8.4°C | 2.6°C | 76 mm | 7.2 | 48 |
| Year | 13.5°C | 6.0°C | 774 mm | 36 | 1,397 |
The table is Casement’s own record, averaged over 1991–2020 from its daily readings (ours, not a Met Éireann table). The rest of the page is Met Éireann’s 1 km grid at Rathnew itself: past 40 km, the station’s frosts and sunshine don’t stand for the town.
How Rathnew 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 of 2,500+ in County Wicklow.
Warmer than it used to be
Rathnew’s 1991–2020 average is 0.2°C warmer than 1981–2010’s. The biggest change is in February (+0.4°C).
A year’s rain is 1,007 mm, up 4% from 973 mm.
Change by month
The two periods share 1991–2010, so the gap is a decade’s step, not the change between two separate 30-year periods.
Rathnew and its neighbours
Rathdrum has the coldest January nights next door (2.3°C, 1.0°C colder). Choose a measure to recolour the map; tap a town for its climate.
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.
| Town | July high | January low | Rain a year |
|---|---|---|---|
| Rathnew | 19.7°C | 3.3°C | 1,007 mm |
| Wicklow 2.3 km | 19.7°C about the same | 3.5°C about the same | 942 mm |
| Ashford 3.5 km | 19.6°C about the same | 2.9°C about the same | 1,086 mm |
| Newcastle 9.4 km | 19.8°C about the same | 3.5°C about the same | 925 mm |
| Newtownmountkennedy 11 km | 19.3°C about the same | 2.7°C 0.6°C colder | 1,120 mm |
| Rathdrum 12 km | 19.6°C about the same | 2.3°C 1.0°C colder | 1,273 mm |
| Kilcoole 13 km | 19.7°C about the same | 3.6°C about the same | 907 mm |
Each town’s colour is Met Éireann’s 1 km grid at its own centre, so towns a few kilometres apart can differ.
Rathnew weather by month
Average daily high and low, mean temperature and rain, 1991–2020, for the town itself (Met Éireann’s 1 km grid).
| Month | High | Low | Mean | Rain |
|---|---|---|---|---|
| January | 8.9°C | 3.3°C | 6.1°C | 98 mm |
| February | 9.2°C | 3.2°C | 6.2°C | 74 mm |
| March | 10.7°C | 4.1°C | 7.4°C | 73 mm |
| April | 12.6°C | 5.5°C | 9.1°C | 70 mm |
| May | 15.2°C | 7.7°C | 11.5°C | 66 mm |
| June | 18.0°C | 10.3°C | 14.2°C | 69 mm |
| July | 19.7°C | 12.1°C | 15.9°C | 62 mm |
| August | 19.6°C | 12.0°C | 15.8°C | 74 mm |
| September | 17.6°C | 10.5°C | 14.0°C | 80 mm |
| October | 14.3°C | 8.1°C | 11.2°C | 114 mm |
| November | 11.3°C | 5.4°C | 8.3°C | 125 mm |
| December | 9.3°C | 3.9°C | 6.6°C | 103 mm |
| Year | 13.9°C | 7.2°C | 10.5°C | 1,007 mm |
Where Rathnew’s numbers come from
Averages over 30 years, not a forecast.
- 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 Rathnew’s population centre (0.2 km away).
- Weather station: the nearest of Met Éireann’s 25 synoptic stations, Casement, 43 km north-west, from Met Éireann’s station list.
- Frosts and degree days: Casement’s daily readings, 1991–2020, in the station table only: past 40 km they don’t stand for the town.
- 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: sunshine, frost days, warm days, snow and wind. Met Éireann publishes no 1991–2020 grid for them, only tables for its stations, so no town has a figure of its own.
Met Éireann 30-year averages · Met Éireann open data. Under Creative Commons Attribution 4.0 (CC BY 4.0).
Questions about Rathnew’s climate
How warm does Rathnew get in summer?
July is the warmest month, with average highs of 19.7°C.
How cold does Rathnew get in winter?
The coldest nights come in February, averaging 3.2°C. Met Éireann counts frosts only at its weather stations, so there is no frost count for the town itself.
How much rain does Rathnew get?
About 1,007 mm a year, more than 55% of Irish towns. November is the wettest month (125 mm) and July the driest (62 mm).
How sunny is it?
Met Éireann publishes its 1991–2020 sunshine averages for its weather stations only, not on the 1 km grid this page reads, so there is no sunshine figure for Rathnew itself. Its nearest synoptic station is Casement.
Are these figures for Rathnew itself?
Yes: they are Met Éireann’s 1991–2020 averages on its 1 km grid, read at Rathnew’s population centre. The nearest of its synoptic weather stations, Casement, is 43 km north-west.
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 Rathnew’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 Rathnew →
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).