Sir George Clarke Simpson KCB CBE FRS[1] HFRSE (2 September 1878 – 1 January 1965) was a British meteorologist.

In 1910, he and his colleague Charles Wright were the meteorologists for Robert Falcon Scott's Antarctic Terra Nova Expedition.

Given the nickname 'Sunny Jim' by the other expedition members, he constructed one of the continent's first weather stations, conducting balloon experiments to test the atmosphere and determine how altitude affects temperature.

From March to May 1916, Simpson had to perform army service as the meteorological adviser to the British Expeditionary Force in Mesopotamia, which now forms part of southern Iraq.

During his tenure as Director, he was engaged in research work in the fields of atmospheric electricity, ionization, radioactivity and solar radiation.

When the Second World War began in 1939, Simpson was recalled from retirement into active service, and was asked to take charge of the Kew Observatory.