Oct 1958

THE WEATHER To most people the term's weather was depressing and disappointing. To those who helped to run the School's weather station it was at least interesting. In this country we happen to live in those latitudes where two air masses, each with different characteristics, are constantly struggling for supremacy. The line along which these masses meet is known as the Polar Front and it is here that depressions form, causing so much of our weather to be changeable and often unpredictable. During the summer the Polar Front is often pushed north by the Azores high pressure system, and it is at such times that we have long periods of hot, dry, settled weather. This summer, however, the Azores high pressure system was never able to take control and most of the time we were subjected to a string of "families" of depressions, blown towards us by the prevailing southwesterly winds through a sort of funnel created by high pressure conditions to the north and south.

There were thus many fluctuations of pressure during the term, usually between low and very low, and the lowest pressure recorded (29.07 in.—about 992 mmb.) occurred on 26th June, when nearly in. of rain fell. The longest spell of comparatively high pressure lasted from 11th June to 18th June and during this period we had the greatest number of successive June days without rain—three !

The rainfall of the term approached 10 in. (9.279 in.) and though May and July both had less rain than in 1957, June more than made up for this and we never had a really prolonged spell of dry weather.

For the statistically minded we had 3.476 ins. in May (3.71 ins. in May, 1957), 3.023 ins. in June and 2.87 ins. in July (3.05 ins. in July, 1957). For a wetter June we have to go back to 1948 when the June rainfall in York was 3.61 ins., while it might be interesting for those who blame nuclear explosions for our weather to know that in May, 1832, York had 5.66 ins. of rain. The greatest rainfall in one day (.6 ins.) fell on 13th May; the longest spell of days with more than .01 ins. of rain lasted for 10 days from 7th May to 16th May, during which time 2.434 ins. fell; and the longest dry period covered a week from 5th July to 1 1 th July, during which time the temperature rose to the maximum for the term-78° F. on 8th July.

Though the rainfall was heavy, the most characteristic feature of the term's weather was the continual low temperatures accompanying the predominantly cloudy skies. In May the temperatures were high for the first day or two and we were lulled into thinking that we were going to have a hot summer at last. However, apart from a warm spell in mid-May, temperatures never rose again above the middle 60's. The minimum temperatures were generally in the middle 40's, though we had ground frost on 12th May. In June the maximum temperature exceeded 70° F. on only 6 days (as compared with 17 in 1957), and on 10th June the temperature did not rise above 49.5° F. Because of the prevalence of cloud, radiation at night was slow and 24