Like much of the British Isles, London has a temperate marine climate so the city rarely sees extreme high or low temperatures. London only gets an average of 1,6 hours of sunshine per year. Despite this, summers are generally warm with 90% of days being over 20 degrees celsius. Heatwaves do occur although serious heatwaves are uncommon. The highest temperature ever recorded in London was 38.1 degrees celsius on 10th August 2003. Travelling on the tube in the height of summer can be particularly hot, overcrowded and uncomfortable as temperatures can reach well above 40 degrees celsius and travellers are advised to carry a bottle of water.
Winters in London can be cold but rarely below freezing. Winter temperatures can range between 16 degrees celsius and -8 degrees celsius. The lowest ever recorded temperature was -21.1 in January 1795. Snow is relatively uncommon although some snow is usually seen a few times a year.
Spring is usually mild during the day with cooler evenings between March and April and generally warm days and mild nights during May. Spring is usually the driest time of the year in London.
Autumn is usually mild but often brings unsettled weather. Temperatures usually remain warm, above 18 degrees celsius until late September.
London is a relatively dry city with regular but generally light rain throughout the year with an average of 583.6 mm every year. In fact, this is lower than many other cities such as New York, Paris and Sydney.