Heathrow Sunshine Hours by Month

In climate discussions, the hours of sunlight reveal much about a location. This page shows the total number of hours of direct sunlight per month and the average hours per day in Heathrow, United Kingdom. These averages rely on historical data collected over 30 years, from 1990 to 2020.

Monthly hours of sunshine

Sunshine in Heathrow varies greatly throughout the year. The sunniest month, July, reaches an impressive 219 hours, while December, the darkest month, offers only 54 hours. The total annual amount of sun is 1675 hours.

Daily hours of sunshine

This means the city can be enjoyed more throughout the sunniest month of July under a blue sky, with approximately 7.3 hours of sunshine daily. In contrast, the city experiences much darker days in December, with only 1.8 hours of sunlight per day.

Average percent of sunshine

On average the sun shines 45% of the time during the day in August, the highest percentage of any month. December has the lowest percentage at 21%.

Heathrow enjoys an average of 1675 hours of sunshine annually. Let’s compare this with some popular tourist destinations:

In Lisbon, Portugal, there are approximately 2801 hours of sunshine annually, highlighting its warm and sunny Mediterranean climate.

In contrast, Reykjavík, Iceland, receives only about 1330 hours of sunshine per year, known for its frequently overcast and rainy skies.

In Seoul, South Korea, there are approximately 2133 hours of sunshine per year, mostly during spring and autumn.

Adelaide, Australia, enjoys 2770 hours of sunshine annually, with long, sunny summers.

November, Heathrow’s wettest month, receives 60 mm (2.4 in) of rainfall and has a maximum daytime temperature of 12°C (54°F). During the driest month March you can expect a temperature of 12°C (54°F).

For more detailed insights into the city’s temperatures, check out our Temperature page. To explore more about precipitation patterns, visit our Heathrow Precipitation page.