Harrow Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Harrow.
Climate overview of Harrow
Temperatures in Harrow, Greater London, United Kingdom, vary greatly throughout the year. July is the hottest month at 23°C (73°F), while January is the coldest at 9°C (48°F).
With around 717 mm (28 in) of annual rain/snowfall, the city has moderate precipitation levels. August is the wettest month and March the driest. It also has warm summers and cold winters. July is the sunniest month, averaging 7.3 hours of sunshine per day.
Harrow Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Harrow - and find the best time to visit.
Monthly Temperature in Harrow
The climate in Harrow is known for significant temperature differences throughout the year, making the weather dynamic. Typically, average maximum daytime temperatures range from a comfortable 23°C (73°F) in July to a chilly 9°C (48°F) in the coolest month, January.
Nights vary from 14°C (57°F) in July to around 3°C (37°F) during the colder months.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Harrow
Generally, Harrow receives mid-range precipitation levels, with 717 mm (28 in) annually. Precipitation levels in Harrow remain relatively steady throughout the year. August has the most rain, with 67 mm (2.6 in) over 12 days. In the driest month March, this drops slightly to 48 mm (1.9 in), making the city's climate fairly predictable. For more details, please visit our Harrow 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 Harrow
For those who appreciate different seasons, Harrow serves as an ideal destination. Expect longer, more sun-filled days in July with an average of 7.3 hours of sunshine daily, and embrace the darker days in December, offering only 1.8 hours of daily sunlight.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Humidity in Harrow by Month
The relative humidity is high throughout the year in Harrow.
The city experiences its highest humidity in November, reaching 81%. In April, the humidity drops to its lowest level at 64%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Wind Speed in Harrow
The average wind speed over the year ranges from 3 m/s (6 knots) to 4 m/s (8 knots). It is lower in May, June, July, August, September, October and November and higher in January, February, March, April and December. What does this mean?
The mean monthly wind speed over the year (meters per second)
Best Time to Visit Harrow
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: June, July, August and September
- Warmest weather: July and August
- Most sunshine: May and July
- Seasonal pattern: Warm summers and cold winters
Frequently asked questions about the climate in Harrow
What is the best time to visit Harrow?
June, July, August and September typically offer the most optimal weather in Harrow. In contrast, January, February and December tend to have less optimal conditions. Harrow has warm summers and cold winters.
What temperatures can I expect in Harrow?
Daytime highs range from 9°C (48°F) in January to 23°C (73°F) in July. Nighttime lows range from 3°C (37°F) to 14°C (57°F). Temperatures vary considerably through the year.
How much rain does Harrow get?
Annual rainfall is around 717 mm (28 in). August is the wettest month with 67 mm (2.6 in), while March is the driest with 48 mm (1.9 in).
How sunny is Harrow?
Harrow receives around 1,675 hours of sunshine per year. July is the sunniest month with 219 hours, while December is the cloudiest with just 54 hours.
Harrow 3-Day Forecast
Harrow on the map
Harrow is highlighted - select any city to see its climate.
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