November 2010

November 2010 has been a very interesting month indeed on the weather front. The month started off on a mild theme with a max of 17.3°C on the 4th and a look back at our records show it is the fourth highest max to be reached in Novembers in the last 24years.

But the majority of November 2010 then saw limited frost, after which several sharp frosts took charge of things. The night of the 27th saw the temperature drop to -8.1°C in the air and -11.7°C on the ground, our coldest night in the air of any month for a decade. As far as Novembers go, in fact, there have only been four nights when the air min plummeted lower than this since 1904 (these are 1904, 1952, 1973, 1978). So what a month temperature wise it has been!!!
Much to my surprise a number of trees have not yet lost all their leaves despite the weather’s best efforts, notably Platanus x hispanica, Acer davidii, Zelkova schneideriana, Pyrus pyrifolia, several Forsythia and the Liquidambar orientalis by the Lake are all stubbornly holding onto their foliage. Many trees did, however, see their canopies disappear rather quickly, with the Pterocarya and Maclura being a couple of good examples.

This November was a dry month with only 24.5mm and 13.1mm of this falling on the 5th (of all nights!). So as we move into December 2010 it is still a wintry scene with an increasing wind chill and very low max temps for the time of year.

John Kapor, Systematics Supervisor and 'the Weatherman'.