Expect Spring a little early again this year

With my tried and trusted ‘First day of Spring’ algorithm, I estimate that Spring 2017 will be around eight days early in 2017, probably occurring on the 13th of March in Central England (fig 1). As usual I estimate it by calculating the degree days from the Winter solstice, and fix the first day of Spring when that count exceeds the mean number of degrees days between Winter Solstice and the Vernal equinox (December 21st and March 20th). And yes, I do know the time of both these can vary by day or so each year. The estimate is based on using the long-term average temperature for future temperatures, so if it’s warmer than usual in the next couple of weeks it may come even sooner, or later if the next six weeks or so are colder than average. That makes this Spring just over three weeks later than it was last year.

Figure 1

Cold Winters mean cold springs, so the Spring of 1963, the third latest since 1772, didn’t happen till the 4th of May that year, likewise a very mild Winter means a very early Spring as in 1989 , the earliest Spring since 1772, which occurred on St Hilary’s day of that year (fig 1). Of course, Central England has warmed since 1772, and the first day of Spring is occurring much earlier, in fact I estimate that Spring is now 20 days earlier than it was in 1772.

Figure 2

About xmetman

An ex-metman passionate about all things to do with weather, climate and clouds
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4 Responses to Expect Spring a little early again this year

  1. xmetman says:

    Thank you!

  2. xmetman says:

    My pleasure – although the weather in our part of the world is fairly quiet at the moment and stories are more difficult to find.

  3. haaark says:

    Another fascinating set of stats that will keep me occupied for hours. Thanks XM.