The sunniest places in Europe yesterday* were to be found on top of mountains, such as the Sonnblick Observatory on mount Hoher Sonnblick in the Austrian Alps and the Zugspitze Observatory in the Wetterstein Mountains in Germany (fig 1).
* This is only the sunniest of the places that report sunshine in their SYNOP. For some reason most of Scandinavia don’t or won’t, the Netherlands and Belgium do report sunshine, but I think they include it in their midnight observations rather than at the more conventional 06 UTC the next day. I should imagine that the sunshine totals north of the Arctic Circle on a cloudless day in summer are 24.0 hours, speaking of which…
Sunshine in Tromso
Here are the climate statistics for Tromso in northern Norway courtesy of Wikipedia (fig 2) which makes interesting reading (crampons when you’re out shopping on the High street and no frost in June since 1997). Having the advantage of sunshine 24 hours a day in summer I would have thought that the average of 221 hours for the month of June would have been a lot higher. Apparently the sunniest month in Norway was in July 1980 when Tromso recorded 430 hours of sunshine. It’s interesting to see the zero hours of sun for the month of December, there can’t be too many weather stations in the world were the average is in fact a constant like this. I still can’t see why across northern Norway the maximum possible sunshine total for June can’t approach 720 hours (30 x 24)? I suppose it’s back to the question of what constitutes ‘bright’ sunshine I raised in the last blog. All I can imagine is that even when the sky is cloudless, the sun when it’s low on an Arctic summer’s night just isn’t strong enough for maybe four or five hours or so to exceed the threshold set for ‘bright’ sunshine.