Abstract
A survey of the 40 years since the late Edward Mawley reorganized the Society's phenological records shows that so satisfactory were his method and selection of events for observation that later developments have followed the lines he laid down. The chief increase has been in stations, which now total to thrice the average number previous to 1920.
The year 1930 was officially characterised as βA Wet Year.β In fact it was the ninth in succession, giving a total rainfall excess of 90 per cent of an ordinary year. Abnormal December and January warmth and excess of sunshine in December, 1929, and November, 1930, make very partial amends for almost continuous adverse conditions in between, save only in June and the brief spell of glorious harvest weather which ended August. Hence, for farm and garden, conditions were as a rule bad. The result on the floral calendar was that no district records were early before the convolvulus in July. Spring flowers in southern parts were almost a week late. But the floral isophenes are naturally much nearer normal than in 1929. The corresponding isakairs are early mainly over southern Scotland and northβwest Ireland; they are latest in west Ireland, central Highlands and scattered English areas. Insects and birds were late; the 20 migrants by two days. A natural exception was the very early first song of the thrush. The spring isophenes can now be compared with the chart of return movements, a matter of decided interest.
Three independent and unusual events are recorded, due apparently to a very exceptional diversion of the warm Atlantic current. Finally abnormal weekly divergences in the three main meteorological factors (cf. monthly values in Tables IAβc) have been based on definite numerical values, thus permitting in future greater precision in comparing year with year.