Rosscahill sits near the top of Irish towns for rain, with 1,469 mm a year
January mornings start at about 3.0°C. In July, afternoons here are cooler than in 94% of Irish towns. Since 1981–2010, the year has warmed by 0.2°C, most of all in April. Homes need heating from November to April, the months averaging under 10°C.
Met Éireann 1991–2020 averages for the town’s own square kilometre.
A year in Rosscahill at a glance
Each month’s typical high and low, in °C.
What stands out about Rosscahill’s climate
Compared with Irish towns, with its place among towns and neighbourhoods of 2,500+ in County Galway beside it.
What a year in Rosscahill feels like
Typical highs and lows by season and by month, from Met Éireann’s 1991–2020 averages.
41 frosts and 3 days of 25°C a year
Air frosts come mostly from October to April, most of all in March (about 9).
Air frosts by month
Average nights below 0°C
Counted from Athenry’s daily readings, 2010–2020, 32 km east of Rosscahill: Met Éireann publishes these for its stations only. At that distance, read them as the area’s climate.
About 1,469 mm of rain a year
December is the wettest month and April the driest. The wettest of 21 towns and neighbourhoods of 2,500+ in County Galway. The wettest month brings about 2.0 times the rain of the driest. Athenry records 1 mm or more on about 193 days a year, and 10 mm on about 39.
Rain by month
Millimetres
Heating a home in Rosscahill
83% of a year’s heating need falls between October and April. Months averaging under 10°C: November to April.
Degree days add up how far each day’s mean temperature falls below 15.5°C over a year.
Living with Rosscahill’s climate
What the averages mean for a garden, a free afternoon and a bad-weather day.
In half of years the last air frost at Athenry comes by 22 April and the first by 4 November: about 196 frost-free days in between.
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; Rosscahill’s hazards page covers the risks.
Flood & hazards →Met Éireann’s nearest station: Athenry
Athenry is 32 km east of Rosscahill, the nearest of the 25 synoptic stations where Met Éireann records the weather around the clock. The station stands 40 m above sea level; Rosscahill’s centre, 11 m.
| Month | High | Low | Rain | Air frosts |
|---|---|---|---|---|
| January | 8.5°C | 2.5°C | 131 mm | 7.8 |
| February | 9.0°C | 2.3°C | 112 mm | 6.8 |
| March | 10.3°C | 2.2°C | 90 mm | 8.5 |
| April | 13.4°C | 4.1°C | 64 mm | 2.5 |
| May | 15.6°C | 6.7°C | 74 mm | 0.5 |
| June | 17.9°C | 9.5°C | 79 mm | 0.0 |
| July | 18.8°C | 11.2°C | 109 mm | 0.0 |
| August | 18.2°C | 10.7°C | 118 mm | 0.0 |
| September | 16.8°C | 9.1°C | 107 mm | 0.1 |
| October | 13.8°C | 6.3°C | 111 mm | 1.4 |
| November | 10.3°C | 3.5°C | 124 mm | 5.7 |
| December | 8.7°C | 2.6°C | 150 mm | 7.7 |
| Year | 13.4°C | 5.9°C | 1,268 mm | 41 |
The table is Athenry’s own record, averaged over 2010–2020 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 Rosscahill itself; the frosts and degree days are this station’s.
How Rosscahill 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 Galway.
Warmer than it used to be
Rosscahill’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, 1,469 mm, is about the same as before.
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.
Rosscahill and its neighbours
Every town next door is within half a degree of Rosscahill in January and July. 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 |
|---|---|---|---|
| Rosscahill | 19.1°C | 3.0°C | 1,469 mm |
| Maigh Cuilinn 6.9 km | 18.7°C about the same | 2.8°C about the same | 1,509 mm |
| Oughterard 7.0 km | 19.2°C about the same | 3.0°C about the same | 1,539 mm |
| Headford 13 km | 19.4°C about the same | 2.7°C about the same | 1,258 mm |
| Rahoon 15 km | 19.2°C about the same | 3.0°C about the same | 1,312 mm |
| Dangan 16 km | 19.1°C about the same | 3.0°C about the same | 1,322 mm |
| Knocknacarra 16 km | 19.0°C about the same | 3.0°C about the same | 1,336 mm |
Each town’s colour is Met Éireann’s 1 km grid at its own centre, so towns a few kilometres apart can differ.
Rosscahill 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 | 8.8°C | 3.0°C | 5.9°C | 156 mm |
| February | 9.3°C | 2.9°C | 6.1°C | 127 mm |
| March | 10.8°C | 3.8°C | 7.3°C | 113 mm |
| April | 13.3°C | 5.2°C | 9.3°C | 86 mm |
| May | 15.9°C | 7.5°C | 11.7°C | 87 mm |
| June | 18.0°C | 10.1°C | 14.1°C | 91 mm |
| July | 19.1°C | 11.9°C | 15.5°C | 101 mm |
| August | 18.9°C | 11.8°C | 15.3°C | 116 mm |
| September | 17.3°C | 10.0°C | 13.7°C | 114 mm |
| October | 14.0°C | 7.5°C | 10.7°C | 143 mm |
| November | 11.0°C | 5.1°C | 8.1°C | 162 mm |
| December | 9.1°C | 3.3°C | 6.2°C | 173 mm |
| Year | 13.8°C | 6.8°C | 10.3°C | 1,469 mm |
How much a month can swing
December swings the most: over 11 years its average ranged from −1.0°C (2010) to 8.1°C (2015). August is the most reliable, staying within 2.2°C.
Where Rosscahill’s numbers come from
Averages over 30 years, not a forecast: the town’s own from Met Éireann’s grid, the frosts 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 Rosscahill’s population centre (0.4 km away).
- Weather station: the nearest of Met Éireann’s 25 synoptic stations, Athenry, 32 km east, from Met Éireann’s station list.
- Frosts and degree days: Athenry’s daily readings from Met Éireann (clidata.met.ie), 2010–2020, 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: sunshine at this station, snow and wind. Met Éireann publishes none of them on a grid; the frosts 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 Rosscahill’s climate
How warm does Rosscahill get in summer?
July is the warmest month, with average highs of 19.1°C.
How cold does Rosscahill get in winter?
The coldest nights come in February, averaging 2.9°C. At Athenry, the nearest Met Éireann station, the air drops below 0°C on about 41 nights a year (2010–2020).
How much rain does Rosscahill get?
About 1,469 mm a year, more than almost every Irish town. December is the wettest month (173 mm) and April the driest (86 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 Rosscahill itself. Its nearest synoptic station is Athenry.
Are these figures for Rosscahill itself?
Partly. The temperatures and rain are Met Éireann’s 1991–2020 averages on its 1 km grid, read at Rosscahill’s population centre; the frosts, degree days and year-to-year swings are those of Athenry, 32 km 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 Rosscahill’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 Rosscahill →
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).