Dumbarton Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Dumbarton.
Climate overview of Dumbarton
The climate in Dumbarton, Strathclyde, United Kingdom, is marked by large temperature swings across the seasons, ranging from 19°C (66°F) in July to 8°C (46°F) in January.
The city has a wet climate, receiving around 1520 mm (60 in) of rain/snowfall per year. Despite the high annual total, it has pleasant summers and cold winters. January is the wettest month. Sunshine peaks in May, when the city sees around 6.3 hours of sunshine per day.
Dumbarton Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Dumbarton - and find the best time to visit.
Monthly Temperature in Dumbarton
In Dumbarton, temperatures differ significantly between summer and winter months. On average, daytime temperatures range from a pleasant 19°C (66°F) in July to a chilly 8°C (46°F) in January.
Nighttime temperatures range from 11°C (52°F) in July to 2°C (36°F) in January.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Dumbarton
Dumbarton experiences significant rain/snowfall throughout the year, averaging 1520 mm (60 in) of precipitation annually. The amount of precipitation varies moderately throughout the year. The wettest month, January, sees around 158 mm (6.2 in) of rainfall, perfect for those who enjoy a bit of rain now and then. The driest month, May, still receives a respectable 96 mm (3.8 in) of rainfall. For more details, please visit our Dumbarton Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Dumbarton
In Dumbarton, summer days are longer and more sunny, with daily sunshine hours peaking at 6.3 hours in May. As the darker season arrives, the brightness of the sun becomes less. January sees a soft sun for only 1.2 hours per average day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Humidity in Dumbarton by Month
The relative humidity is high throughout the year in Dumbarton.
The city experiences its highest humidity in January, reaching 87%. In May, the humidity drops to its lowest level at 68%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Best Time to Visit Dumbarton
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: May, July and August
- Warmest weather: June, July and August
- Most sunshine: May
- Seasonal pattern: Pleasant summers and cold winters
Frequently asked questions about the climate in Dumbarton
What is the best time to visit Dumbarton?
May, July and August typically offer the most optimal weather in Dumbarton. In contrast, January, February, March, October, November and December tend to have less optimal conditions. Dumbarton has pleasant summers and cold winters.
What temperatures can I expect in Dumbarton?
Daytime highs range from 8°C (46°F) in January to 19°C (66°F) in July. Nighttime lows range from 2°C (36°F) to 11°C (52°F). Temperatures vary considerably through the year.
How much rain does Dumbarton get?
Annual rainfall is around 1520 mm (60 in). January is the wettest month with 158 mm (6.2 in), while May is the driest with 96 mm (3.8 in).
How sunny is Dumbarton?
Dumbarton receives around 1,290 hours of sunshine per year. May is the sunniest month with 188 hours, while January is the cloudiest with just 37 hours.
Dumbarton 3-Day Forecast
Dumbarton on the map
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