Tuesday, 22 December 2015

Winter solstice? Not necessarily!

Being mildly pagan, in an uninformed and romantic way, I've always welcomed the Winter solstice. Even in such a mild winter as this, it is still a time of year that lacks sunlight and day length (as I recently posted about). But when we get to December 21st things start to happen, as it is the day that has the shortest amount of daylight. So the following day - today! - the time we spend in daylight is longer... er, not necessarily so.
Each year this can change. In most years the shortest day is indeed December 21st, but in some (as in this year) it can occur on December 22nd. In very rare cases it can happen on December 20th or 23rd. The last time the latter year played host to it was 1903, and the next will be 2303. Confused? The Daily Telegraph website explains:
"The December solstice happens at the same instant for all of us, everywhere on Earth. This year the solstice occurs on Tuesday December 22nd at 04:49 GMT (Universal time) with the sun rising over Stonehenge in Wiltshire at 08:04.
The winter solstice happens every year when the Sun reaches its most southerly declination of -23.5 degrees. In other words, when the North Pole is tilted furthest – 23.5 degrees – away from the Sun, delivering the fewest hours of sunlight of the year. 
The Sun is directly overhead of the Tropic of Capricorn in the Southern Hemisphere during the December solstice and is closer to the horizon than at any other time in the year, meaning shorter days and longer nights. 
The day after the winter solstice marks the beginning of lengthening days, leading up to the summer solstice in June."

So, the shortest day in 2015 is in fact today. It will start getting lighter tomorrow.

I can almost hear those Swifts screaming from here...

8 comments:

  1. My second favourite day Steve, for the reasons that you give. My favourite day? - New Year's Day. The day that all that festivities rubbish is behind us and we can look forward to Spring and summer and of course longer days, going to bed at gone 10.00 at night with part daylight still showing outside. How can it being damp and dark by 4.30 possibly be better than that.
    Swifts screaming, quite a while since I heard that on Sheppey, sad to say.

    ReplyDelete
    Replies
    1. Derek, here in Banstead, the screaming of swifts was a taken for granted part of summer evenings. But not this year. It was worryingly quiet.

      Delete
    2. Swifts at screaming level have declined to virtually zero over the past ten years or so in my part of Banstead. Plastic barge boards and soffits have put paid to their breeding in the sermis off the High Street! Spraying on the surrounding farms have killed off their food supply. Desperate!

      Delete
    3. Sad indeed John. I like to sit in the garden during the evenings in June and lose myself in them, sometimes 20-30 strong, all chasing and screaming. To lose that will be very sad indeed.

      Delete
  2. I don't mind the shorter days, really, because I love winter. I love all four seasons, actually. Merry Christmas to you and warm greetings from Montreal, Canada. :) My father's parents are from Kent.

    ReplyDelete
    Replies
    1. And warm greetings to you too Linda, from a very dull, wet and mild England.

      Delete
  3. not so fast ... the earliest dusk and latest dawn are twenty or so days apart this year. Weird.

    http://www.timeanddate.com/sun/uk/london?month=12&year=2015

    ReplyDelete
    Replies
    1. You are right DD. Confusion reigns, at least with me, as although the daylight now lengthens, dawn carries on to arrive later, but the evenings become lighter.

      Delete