The four seasons

Advertisment
  • Snowdrops burgeoning at Rococo Gardens in Painswick, Gloucestershire, on 11 January. Photo: Tim Ireland/PA Wire

    At East Lambrook Manor Gardens, Somerset, head gardener Mark Stainer tidies a bed of early variety Daffodil Narcissus, which even though an early bloomer should only begin to flower in February, not by 10 January as these have. Photo: Ben Birchall/PA Wire

    A spring-flowering Symphytum Tuberosum shows dozens of slender blue flowers in January, rather than the expected months of April, May and June, at East Lambrook Manor Gardens, Somerset. Photo: Ben Birchall/PA Wire

    A Helleborus Orientalis, which usually flowers from late February to March, has been in bloom since December at East Lambrook Manor Gardens, Somerset. Photo: Ben Birchall/PA Wire

  • The four seasons
    13.01.2012 10:38

     

    For the sake of simplicity and tradition the calendar year remains divided into four seasons of three months each.

    Astronomically these run between solstices and equinoxes but meteorologically and popularly they split into calendar months, with winter of course straddling the year end.

    Every so often there is an assertion that the seasons have changed – spring coming earlier or winter later – and that perhaps we should review the way they are differentiated. Indeed, daffodils are already blooming in some parts of the country because of the mild winter thus far, and in 2011 summer was cool with respect to its average and compared with the warm spring and autumn either side, in a peculiar year for meteorology that was the second warmest on record.

    However, this ignores the fact that there is no reason why wintry conditions, for example, should not end later in the year. Moreover, the seasons are inapplicable in some other parts of the world, particularly close to the equator.

    We must accept that the seasons are an imperfect measure of the year but they are a neat enough approximation, they have become entrenched, and we all realise that “unseasonal” weather can happen at any time.

    Having said that, in 1954 the great climatologist Hubert Lamb proposed a year divided into five “natural seasons”. He recognized five periods during the year wherein the weather can be reasonably consistent and persistent (although not necessarily of the same type from year to year) and the transitions of which can be quite well identified. The wonder and surprise of the British climate, however, is that it can have such variety from one year to the next, and no system can hope adequately to describe that consistently.

    The seasons that Professor Lamb suggested were: Spring, 30 March to 17 June; High Summer, 18 June to 9 September; Autumn, 10 September to 19 November; Early Winter, 20 November to 19 January; and Late Winter, 20 January to 29 March.

    If his “singularities” are read literally then perhaps we could expect a change in pattern starting at the end of next week. The coin is still in the air as far as that is concerned, and before that we are already going to see a marked change through Friday and the weekend to calm, dry, cold and frosty weather. But we wouldn’t call it a different season.