Climate, London

It has been said that the UK has the best climate and the worst weather of anywhere in the world. Winters are fairly mild and summers are for the most part, quite cool, but you have to be prepared for strong winds and heavy rain all year around.

London has a temperate marine climate (Koppen climate classification Cfb), like much of the British Isles, so the city rarely sees extremely high or low temperatures. Summers are warm with average high temperatures of 21 °C (70 °F) – 24 °C (75 °F) and

lows of 11 °C (52 °F) – 14 °C (57 °F). But temperatures can exceed 25 °C (77 °F) on many days, and in almost every year they exceed 30 °C (86 °F) on some days. The highest temperature ever recorded was 39 °C (102 °F) [85] on 10 August 2003. Winters in London are chilly, but rarely below freezing with daytime highs around 8 °C (46 °F) – 12 °C (54 °F), while Spring has mild days and cool evenings. The lowest ever recorded temperature was -21 °C (-5.8 °F) in 1795 and 1796. The lowest in recent years was -10 °C (14.0 °F) on 14 January 1982. Autumn is usually mild but often unsettled as colder air from the north and warmer air from the south meet.

London is a relatively dry city with regular but generally light precipitation throughout the year, with an average of 583.6 millimetres (22.98 in) every year. Snow is relatively uncommon, particularly because heat from the urban area can make London up to 5 °C (9 °F) warmer than the surrounding areas in winter. Some snowfall, however, is usually seen up to a few times a year. The snowfall of February 2009 was the heaviest London had seen for 18 years. London is in USDA Hardiness zone 9, and AHS Heat Zone 2.

Although extreme weather does not happen very often, deep depressions have been known to pass through London, like the Great Storm of 1987. Tornados are rare, but the Kensal Green area of the city was hit by the 2006 London tornado causing £10 million of damage and injuring 6 people. In the second half of the 19th century and the first half of the 20th, London was noted for its dense fogs and smogs. Following the deadly Great Smog of 1952, the Clean Air Act 1956 was passed, leading to the decline of such severe pollution in the capital.

Despite perhaps an unfair reputation for being unsettled, London enjoys a dry and mild climate on average. Only one in three days will bring rain, and often only for a short period. From June through to September the average daily high temperatures peak at over 20C, with July and August being the warmest months at 23C. The highest temperature since 2000 was recorded one August at 38C. This means that London can feel hot and humid in the summer months. Winter days are rarely cold and frost is rather uncommon, and while sunshine is at a premium and wet days are more common, the average daily maximum is 8C in December and January, making London milder than most nearby continental European capital cities.