Photo: George Rankin · CC BY-SA 2.0Bonhill sits near the top of UK towns for rain, with 1,506 mm (59 in) a year
A warm July spell here typically peaks at 19.4°C (67°F). Days of 25°C are scarce: about 2 a year, fewer than in 93% of UK towns. Seasons differ by 18°C, from the coldest nights to the warmest afternoons. Long walks are most pleasant from June to August, when afternoons reach 18–19°C.
Met Office 1991–2020 averages for the town itself.
A year in Bonhill at a glance
Each month’s typical high and low, in °C.
What a year in Bonhill feels like
Typical highs and lows by season and by month, from the Met Office’s 1991–2020 averages.
About 1,506 mm of rain a year
January is the wettest month and April the driest. About 54 days a year bring 10 mm (0.4 in) or more. The wettest of 8 West Dunbartonshire towns of 2,500+.
Rain by month
Millimetres
Sunshine by month
Hours of bright sunshine at Paisley
41 air frosts and 2 days of 25°C a year
On about 41 nights a year the air drops below freezing, and on about 1 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 11 miles south-east of Bonhill, 32 m (105 ft) above sea level. It is the nearest of the 37 long-running stations the Met Office publishes in full.
| 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 Bonhill 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 West Dunbartonshire 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 |
|---|---|---|---|
| Bonhill | 19.4°C | 1.5°C | 1,506 mm |
| Alexandria 1.1 mi | 19.2°C about the same | 2.0°C 0.6°C milder | 1,497 mm |
| Balloch and Haldane 1.5 mi | 19.4°C about the same | 2.1°C 0.7°C milder | 1,482 mm |
| Dumbarton 2.3 mi | 19.3°C about the same | 1.8°C about the same | 1,305 mm |
| Port Glasgow 5.5 mi | 18.8°C 0.6°C cooler | 1.7°C about the same | 1,701 mm |
| Bishopton 5.7 mi | 19.2°C about the same | 1.4°C about the same | 1,360 mm |
| Bowling and Old Kilpatrick 5.7 mi | 18.2°C 1.2°C cooler | 1.7°C about the same | 1,431 mm |
Bonhill 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 | 6.4°C 43°F | 1.5°C 35°F | 3.9°C | 184 mm 7.2 in |
| February | 7.6°C 46°F | 2.1°C 36°F | 4.9°C | 135 mm 5.3 in |
| March | 9.3°C 49°F | 3.0°C 37°F | 6.1°C | 116 mm 4.6 in |
| April | 12.3°C 54°F | 4.6°C 40°F | 8.3°C | 77 mm 3.0 in |
| May | 15.6°C 60°F | 7.1°C 45°F | 11.3°C | 81 mm 3.2 in |
| June | 18.0°C 64°F | 9.9°C 50°F | 13.7°C | 92 mm 3.6 in |
| July | 19.4°C 67°F | 11.6°C 53°F | 15.3°C | 99 mm 3.9 in |
| August | 19.0°C 66°F | 11.6°C 53°F | 15.1°C | 114 mm 4.5 in |
| September | 16.5°C 62°F | 9.8°C 50°F | 13.1°C | 120 mm 4.7 in |
| October | 13.0°C 55°F | 6.9°C 44°F | 9.9°C | 167 mm 6.6 in |
| November | 9.5°C 49°F | 4.3°C 40°F | 6.9°C | 156 mm 6.1 in |
| December | 7.4°C 45°F | 2.1°C 36°F | 4.7°C | 166 mm 6.5 in |
| Year | 12.8°C | 6.2°C | 9.4°C | 1,506 mm |
Where Bonhill’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 Bonhill’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, 11 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 Bonhill’s climate
How warm does Bonhill get in summer?
July is the warmest month, with average highs of 19.4°C (67°F). About 2 days a year reach 25°C (77°F), fewer than 93% of UK towns.
How cold does Bonhill get in winter?
January nights average 1.5°C (35°F). The air drops below freezing on about 41 nights a year, and about 1 days a year stay below freezing all day.
How much rain does Bonhill get?
About 1,506 mm (59 in) a year, more than 96% of UK towns. January is the wettest month (184 mm) and April the driest (77 mm).
How sunny is it?
The nearest Met Office station with a sunshine record, Paisley (11 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 Bonhill. 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 Bonhill →
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.