Harthill has some of the coldest winter nights among UK towns
Peak summer warmth arrives in July, with afternoons near 18.6°C (66°F). October is the wettest month, April the driest. Its July afternoons stay fresher than in 96% of UK towns. The heating season runs October to May: each of those months averages under 10°C.
Met Office 1991–2020 averages for the town itself.
A year in Harthill at a glance
Each month’s typical high and low, in °C.
What a year in Harthill feels like
Typical highs and lows by season and by month, from the Met Office’s 1991–2020 averages.
About 1,114 mm of rain a year
October is the wettest month and April the driest. About 32 days a year bring 10 mm (0.4 in) or more. 12th wettest of 24 North Lanarkshire towns of 2,500+.
Rain by month
Millimetres
Sunshine by month
Hours of bright sunshine at Paisley
A frosty town: 66 air frosts and 2 days of 25°C a year
On about 66 nights a year the air drops below freezing, and on about 2 days it stays below freezing all day. About 2 days a year reach 25°C (77°F).
Day counts are 1991–2020 averages from the Met Office’s 2 km grid. The Met Office calls a day of 25°C or more a summer day and a night below 0°C an air frost; ground frosts, on grass, come more often.
The Met Office station at Paisley
Paisley is 26 miles west of Harthill, 32 m (105 ft) above sea level. It is the nearest of the 37 long-running stations the Met Office publishes in full; at that distance read it for sunshine and the station’s own record, not as the town’s figures.
| Month | High | Low | Rain | Air frosts | Sun (hours) |
|---|---|---|---|---|---|
| January | 7.1°C | 1.9°C | 147 mm | 8.5 | 39 |
| February | 7.8°C | 2.1°C | 111 mm | 7.3 | 69 |
| March | 9.9°C | 3.2°C | 100 mm | 4.3 | 103 |
| April | 12.9°C | 5.1°C | 72 mm | 0.9 | 133 |
| May | 16.1°C | 7.4°C | 63 mm | 0.1 | 184 |
| June | 18.3°C | 10.2°C | 67 mm | 0.0 | 161 |
| July | 19.7°C | 12.1°C | 76 mm | 0.0 | 149 |
| August | 19.5°C | 11.9°C | 90 mm | 0.0 | 151 |
| September | 16.7°C | 9.9°C | 99 mm | 0.0 | 116 |
| October | 12.9°C | 6.8°C | 134 mm | 0.9 | 89 |
| November | 9.6°C | 4.3°C | 133 mm | 3.6 | 54 |
| December | 6.8°C | 1.5°C | 136 mm | 9.7 | 36 |
| Year | 13.1°C | 6.4°C | 1,229 mm | 35 | 1,282 |
Met Office historic station data, Paisley, 1991–2020 months averaged (a month needs 20 of the 30 years; estimated values counted, missing months left out). Sunshine: Campbell-Stokes recorder.
How Harthill compares
Against the 2,537 towns and cities of 2,500 or more across the UK, each with its own Met Office averages, and its place among North Lanarkshire towns that size.
Nearby towns’ climate
The nearest towns of 1,000+ within 12 miles: a hill, a valley or the sea can make a real difference over a few miles.
| Town | July high | January low | Rain a year |
|---|---|---|---|
| Harthill | 18.6°C | 0.4°C | 1,114 mm |
| Whitburn 2.4 mi | 18.6°C about the same | 0.4°C about the same | 1,119 mm |
| Fauldhouse 2.9 mi | 17.5°C 1.1°C cooler | 0.3°C about the same | 1,315 mm |
| Armadale 3.2 mi | 18.7°C about the same | 0.8°C about the same | 1,053 mm |
| Shotts 3.3 mi | 18.0°C 0.6°C cooler | 0.3°C about the same | 1,193 mm |
| Blackburn 5.1 mi | 18.5°C about the same | 1.1°C 0.7°C milder | 1,055 mm |
| Bathgate 5.2 mi | 18.4°C about the same | 0.9°C 0.5°C milder | 1,065 mm |
Harthill weather by month
Average daily high and low, mean temperature and rain, 1991–2020, for the town itself (the Met Office’s HadUK-Grid).
| Month | High | Low | Mean | Rain |
|---|---|---|---|---|
| January | 5.7°C 42°F | 0.4°C 33°F | 3.1°C | 117 mm 4.6 in |
| February | 6.5°C 44°F | 0.4°C 33°F | 3.5°C | 97 mm 3.8 in |
| March | 8.5°C 47°F | 1.6°C 35°F | 5.0°C | 88 mm 3.5 in |
| April | 11.2°C 52°F | 3.1°C 38°F | 7.2°C | 61 mm 2.4 in |
| May | 14.4°C 58°F | 5.5°C 42°F | 9.9°C | 70 mm 2.7 in |
| June | 16.9°C 62°F | 8.3°C 47°F | 12.6°C | 72 mm 2.8 in |
| July | 18.6°C 66°F | 10.1°C 50°F | 14.4°C | 89 mm 3.5 in |
| August | 18.3°C 65°F | 9.9°C 50°F | 14.0°C | 100 mm 3.9 in |
| September | 15.8°C 60°F | 8.1°C 47°F | 12.0°C | 85 mm 3.3 in |
| October | 12.1°C 54°F | 5.3°C 41°F | 8.7°C | 121 mm 4.8 in |
| November | 8.4°C 47°F | 2.5°C 36°F | 5.5°C | 106 mm 4.2 in |
| December | 6.2°C 43°F | 0.3°C 33°F | 3.1°C | 110 mm 4.3 in |
| Year | 11.9°C | 4.6°C | 8.2°C | 1,114 mm |
Where Harthill’s numbers come from
Averages over 30 years, not a forecast.
- Mean temperature, rain and day counts: HadUK-Grid 1991–2020 averages for the Met Office 2 km grid square nearest Harthill’s centre (the town is smaller than one square).
- Highs and lows: the Met Office publishes average daily maxima and minima on its 12 km grid; each is moved by the difference between the town’s 2 km mean temperature and the 12 km square’s, which carries the town’s own height and setting over.
- Weather station and sunshine: Met Office historic station data for Paisley, 26 miles away, months of 1991–2020 averaged.
- Comparisons: every town and city of 2,500 or more across the UK, all four nations, read the same way.
Met Office HadUK-Grid · Met Office Climate Data Portal · Historic station data. Open Government Licence v3.0.
Questions about Harthill’s climate
How warm does Harthill get in summer?
July is the warmest month, with average highs of 18.6°C (66°F). About 2 days a year reach 25°C (77°F), fewer than 95% of UK towns.
How cold does Harthill get in winter?
December nights average 0.3°C (33°F). The air drops below freezing on about 66 nights a year, and about 2 days a year stay below freezing all day.
How much rain does Harthill get?
About 1,114 mm (44 in) a year, more than 85% of UK towns. October is the wettest month (121 mm) and April the driest (61 mm).
How sunny is it?
The nearest Met Office station with a sunshine record, Paisley (26 miles away), averages 1,282 hours of bright sunshine a year. Sunshine isn’t on the town grid, so this is the station’s figure.
Where do these figures come from?
The Met Office’s HadUK-Grid 1991–2020 averages, which turn thousands of weather stations into a map of the UK in 2 km squares; the page reads the squares inside Harthill. They are 30-year averages, not a forecast.
Contains Met Office data © Crown copyright 2026, Open Government Licence v3.0. HadUK-Grid 1991–2020 averages via the Met Office Climate Data Portal; station averages from Met Office historic station data. Today’s forecast for Harthill →
Contains public sector information licensed under the Open Government Licence v3.0. Contains HM Land Registry data © Crown copyright and database right 2026. Contains OS data © Crown copyright and database right 2026 (ONS boundaries). Northern Ireland: Source: NISRA; contains Land & Property Services data and Ordnance Survey of Northern Ireland information, © Crown copyright, licensed under the Open Government Licence v3.0. Scotland: contains National Records of Scotland data, Registers of Scotland data and SEPA data, © Crown copyright / © SEPA 2025, licensed under the Open Government Licence v3.0.