Historical Ranked Annual Data - Day Maximum (09-21) / °C
Day Maximum (09-21) annual extremes: highest and lowest annual ranges (daily max − min).
There are 27 valid years for the chosen period from 2000 to present in London, NW3. Data for Day Maximum (09-21) begins in 1881.
*Data from before 2009 are mostly from the historical site at Whitestone Pond in Hampstead. Where data from that record is missing, other nearby sites were used, including St James Park, Heathrow, and Kew Gardens (pre-1910). Best efforts have been made to adjust for site differences, but uncertainties are somewhat greater for this data. I am grateful to the Met Office for making this data available for free through the MIDAS Open database.
Highest air temperature during the daytime window 09:00 to 21:00 local time.