By the beginning of March, the longest winter nights have passed in the northern hemisphere for another year as the day length increases ahead of the equinox later in the month. Meteorologically, spring begins on 1st March and ends on 31st May, which is for statistical purposes and historical records. For many people the season changeover is when the oscillating date of the spring equinox occurs, which this year is 20th March. Although spring can be determined by calendar dates, the natural variability within the atmosphere means that, as far as the weather is concerned, year to year differences vary widely. These changeable weather patterns can have big impacts on how flora and fauna respond through the season. John Hammond, a forecaster at the Met Office explains more on the BBC blog 23 degrees.
More details and provisional statistics on the Winter of 2010/11 will be available in the next day or so once all the data has been collected and compiled.