Summers in Castlefinn are cooler than in 92% of Irish towns
Deep winter brings January lows near 2.2°C. Rain peaks in December and eases off in April. Its yearly rainfall tops that of 83% of Irish towns. Garden chairs stay out from June to September, the months with highs of 17–19°C.
Met Éireann 1991–2020 averages for the town’s own square kilometre.
A year in Castlefinn at a glance
Each month’s typical high and low, in °C.
What stands out about Castlefinn’s climate
Compared with Irish towns, with its place among towns of 2,500+ in County Donegal beside it.
What a year in Castlefinn feels like
Typical highs and lows by season and by month, from Met Éireann’s 1991–2020 averages.
About 1,151 mm of rain a year
December is the wettest month and April the driest. 7th wettest of 7 towns of 2,500+ in County Donegal. The wettest month brings about 1.9 times the rain of the driest.
Rain by month
Millimetres
Living with Castlefinn’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; Castlefinn’s hazards page covers the risks.
Flood & hazards →Met Éireann’s nearest station: Finner
Finner is 55 km south-west of Castlefinn, the nearest of the 25 synoptic stations where Met Éireann records the weather around the clock.
| Distance from the town | 55 km south-west |
| Station altitude | 33 m |
| Town altitude (its centre) | 9 m |
The figures on this page are not this station’s readings: they are Met Éireann’s 1 km grid at Castlefinn itself, which it builds from its whole network of stations.
How Castlefinn 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 Donegal.
Warmer than it used to be
Castlefinn’s 1991–2020 average is 0.3°C warmer than 1981–2010’s. The biggest change is in February (+0.4°C).
A year’s rain is 1,151 mm, up 4% from 1,109 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.
Castlefinn and its neighbours
Every town next door is within half a degree of Castlefinn 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 |
|---|---|---|---|
| Castlefinn | 19.2°C | 2.2°C | 1,151 mm |
| Lifford 7.3 km | 19.1°C about the same | 2.2°C about the same | 1,070 mm |
| Raphoe 7.5 km | 18.7°C 0.5°C cooler | 1.8°C about the same | 1,245 mm |
| Convoy 8.0 km | 18.9°C about the same | 2.0°C about the same | 1,336 mm |
| Ballybofey-Stranorlar 12 km | 19.1°C about the same | 2.1°C about the same | 1,395 mm |
Each town’s colour is Met Éireann’s 1 km grid at its own centre, so towns a few kilometres apart can differ.
Castlefinn 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 | 2.2°C | 5.1°C | 126 mm |
| February | 8.6°C | 2.1°C | 5.4°C | 100 mm |
| March | 10.4°C | 3.1°C | 6.8°C | 88 mm |
| April | 12.9°C | 4.6°C | 8.8°C | 71 mm |
| May | 15.8°C | 6.9°C | 11.4°C | 72 mm |
| June | 17.9°C | 9.6°C | 13.8°C | 76 mm |
| July | 19.2°C | 11.5°C | 15.4°C | 83 mm |
| August | 19.0°C | 11.3°C | 15.1°C | 91 mm |
| September | 17.0°C | 9.4°C | 13.2°C | 86 mm |
| October | 13.6°C | 6.8°C | 10.2°C | 108 mm |
| November | 10.4°C | 4.3°C | 7.3°C | 118 mm |
| December | 8.3°C | 2.4°C | 5.3°C | 133 mm |
| Year | 13.4°C | 6.2°C | 9.8°C | 1,151 mm |
Where Castlefinn’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 Castlefinn’s population centre (0.4 km away).
- Weather station: the nearest of Met Éireann’s 25 synoptic stations, Finner, 55 km south-west, from Met Éireann’s station list.
- Frosts and degree days: Finner’s daily readings, 2011–2020, 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 Castlefinn’s climate
How warm does Castlefinn get in summer?
July is the warmest month, with average highs of 19.2°C.
How cold does Castlefinn get in winter?
The coldest nights come in February, averaging 2.1°C. Met Éireann counts frosts only at its weather stations, so there is no frost count for the town itself.
How much rain does Castlefinn get?
About 1,151 mm a year, more than 83% of Irish towns. December is the wettest month (133 mm) and April the driest (71 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 Castlefinn itself. Its nearest synoptic station is Finner.
Are these figures for Castlefinn itself?
Yes: they are Met Éireann’s 1991–2020 averages on its 1 km grid, read at Castlefinn’s population centre. The nearest of its synoptic weather stations, Finner, is 55 km south-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 Castlefinn’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 Castlefinn →
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).