How many days until summer?

Astronomical summer begins at the June solstice, on 21 June in most years, when the northern hemisphere is tilted furthest towards the sun. The Met Office also publishes meteorological seasons that start on the 1st of the month, and both are in everyday use in Britain — this countdown follows the solstice, the version printed on calendars and marked at Stonehenge.

The solstice is the longest day of the year, and in Britain that means a great deal. London gets close to sixteen and three quarter hours of daylight, Edinburgh over seventeen and a half, and in Shetland the sun barely sets at all — the "simmer dim", where midsummer twilight lasts through the night. Sunset in the south is around a quarter past nine.

Summer here is a season of specific fixtures rather than reliable weather: Wimbledon from the end of June, the Glastonbury festival, county cricket, Cowes week, school sports days, and beer gardens rammed the moment the sun appears. Hosepipe bans and thunderstorms arrive in roughly equal measure, and nobody plans an outdoor event without a wet weather option.

From the solstice onward the days begin shortening again, almost imperceptibly at first. The countdown here ends at the midnight that opens the solstice date, so the number shown is the wait until summer's first day starts rather than until the precise astronomical moment.