Roosky has colder winter nights than 85% of Irish towns
Peak summer warmth arrives in July, with afternoons near 19.6°C. The rainiest month is December; the driest is May. In July, afternoons here are cooler than in 77% of Irish towns. Expect about 52 frosty starts a year, nights when the air falls below freezing.
Met Éireann 1991–2020 averages for the town’s own square kilometre.
A year in Roosky at a glance
Each month’s typical high and low, in °C.
What stands out about Roosky’s climate
Compared with Irish towns, with its place among towns of 2,500+ in County Roscommon beside it.
What a year in Roosky feels like
Typical highs and lows by season and by month, from Met Éireann’s 1991–2020 averages.
52 frosts and 4 days of 25°C a year
Air frosts come mostly from October to May, most of all in March (about 10).
Air frosts by month
Average nights below 0°C
Counted from Mount Dillon’s daily readings, 2004–2020, 12 km south of Roosky: Met Éireann publishes these for its stations only.
About 1,071 mm of rain a year
December is the wettest month and May the driest. 3rd wettest of 3 towns of 2,500+ in County Roscommon. The wettest month brings about 1.6 times the rain of the driest. Mount Dillon records 1 mm or more on about 175 days a year, and 10 mm on about 30.
Rain by month
Millimetres
Heating a home in Roosky
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 Roosky’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 Mount Dillon comes by 30 April and the first by 9 October: about 162 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; Roosky’s hazards page covers the risks.
Flood & hazards →Met Éireann’s nearest station: Mount Dillon
Mount Dillon is 12 km south of Roosky, the nearest of the 25 synoptic stations where Met Éireann records the weather around the clock. The station stands 39 m above sea level; Roosky’s centre, 44 m.
| Month | High | Low | Rain | Air frosts |
|---|---|---|---|---|
| January | 7.9°C | 1.9°C | 110 mm | 8.6 |
| February | 8.6°C | 1.7°C | 79 mm | 9.1 |
| March | 10.4°C | 1.8°C | 81 mm | 10.1 |
| April | 13.5°C | 3.2°C | 61 mm | 4.6 |
| May | 16.1°C | 5.8°C | 73 mm | 1.4 |
| June | 18.8°C | 8.6°C | 82 mm | 0.0 |
| July | 19.9°C | 10.5°C | 84 mm | 0.0 |
| August | 18.8°C | 10.2°C | 105 mm | 0.1 |
| September | 17.2°C | 8.0°C | 80 mm | 0.6 |
| October | 13.9°C | 5.6°C | 101 mm | 2.8 |
| November | 10.1°C | 3.3°C | 104 mm | 6.4 |
| December | 8.1°C | 2.0°C | 118 mm | 8.5 |
| Year | 13.6°C | 5.2°C | 1,076 mm | 52 |
The table is Mount Dillon’s own record, averaged over 2004–2020 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 Roosky itself; the frosts and degree days are this station’s.
How Roosky 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 Roscommon.
Warmer than it used to be
Roosky’s 1991–2020 average is 0.2°C warmer than 1981–2010’s. The biggest change is in April (+0.4°C).
A year’s rain is 1,071 mm, up 2% from 1,050 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.
Roosky and its neighbours
Every town next door is within half a degree of Roosky 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 |
|---|---|---|---|
| Roosky | 19.6°C | 2.1°C | 1,071 mm |
| Drumlish 10 km | 19.5°C about the same | 2.0°C about the same | 1,106 mm |
| Mohill 11 km | 19.5°C about the same | 2.0°C about the same | 1,112 mm |
| Longford 14 km | 19.7°C about the same | 2.1°C about the same | 1,015 mm |
| Carrick-On-Shannon 17 km | 19.4°C about the same | 2.1°C about the same | 1,123 mm |
| Lanesborough-Ballyleague 18 km | 19.6°C about the same | 2.1°C about the same | 1,041 mm |
Each town’s colour is Met Éireann’s 1 km grid at its own centre, so towns a few kilometres apart can differ.
Roosky 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 | 8.0°C | 2.1°C | 5.0°C | 110 mm |
| February | 8.7°C | 2.0°C | 5.3°C | 84 mm |
| March | 10.5°C | 2.9°C | 6.7°C | 81 mm |
| April | 13.2°C | 4.4°C | 8.8°C | 71 mm |
| May | 16.0°C | 6.8°C | 11.4°C | 69 mm |
| June | 18.3°C | 9.5°C | 13.9°C | 77 mm |
| July | 19.6°C | 11.4°C | 15.5°C | 84 mm |
| August | 19.2°C | 11.2°C | 15.2°C | 90 mm |
| September | 17.2°C | 9.2°C | 13.2°C | 78 mm |
| October | 13.7°C | 6.5°C | 10.1°C | 105 mm |
| November | 10.3°C | 4.0°C | 7.2°C | 109 mm |
| December | 8.2°C | 2.3°C | 5.2°C | 113 mm |
| Year | 13.6°C | 6.0°C | 9.8°C | 1,071 mm |
How much a month can swing
December swings the most: over 17 years its average ranged from −1.5°C (2010) to 7.5°C (2015). August is the most reliable, staying within 2.2°C.
Where Roosky’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 Roosky’s population centre (0.0 km away).
- Weather station: the nearest of Met Éireann’s 25 synoptic stations, Mount Dillon, 12 km south, from Met Éireann’s station list.
- Frosts and degree days: Mount Dillon’s daily readings from Met Éireann (clidata.met.ie), 2004–2020, 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 Roosky’s climate
How warm does Roosky get in summer?
The warmest month is July, when afternoons average 19.6°C.
How cold does Roosky get in winter?
February nights average 2.0°C, the coldest of the year. At Mount Dillon, the nearest Met Éireann station, the air drops below 0°C on about 52 nights a year (2004–2020).
How much rain does Roosky get?
About 1,071 mm a year, more than 67% of Irish towns. December is the wettest month (113 mm) and May the driest (69 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 Roosky itself. Its nearest synoptic station is Mount Dillon.
Are these figures for Roosky itself?
Partly. The temperatures and rain are Met Éireann’s 1991–2020 averages on its 1 km grid, read at Roosky’s population centre; the frosts, degree days and year-to-year swings are those of Mount Dillon, 12 km south, 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 Roosky’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 Roosky →
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).