Physical Features 1 1 



in late August outside the town area. Records in the sheltered grounds of 

 the Radcliffe Observatory, however, are often 2 or more above those of 

 outlying districts. No frost has been recorded in July for 60 years, but 

 a drop to 33-5 occurred in July 1918. 



The lowest temperatures recorded on the grass are 2-7 F. on Feb. 5, 

 1917, and 0-1, Feb. 8, 1895 (the coldest winter of modern times). A drop 

 to zero, as a cold blizzard on the afternoon of Feb. 4, 1917, and on the cold 

 Christmas Eve of 1860, is very exceptional. Frosts of more than ten degrees 

 (22 F.) may be considered less usual, and long spells of frost are rare. The 

 severe frost of 1895, over a period of practically 6 weeks, established a modern 

 record. Snow-fall is inconsiderable ; wholly wanting in some winters (1920); 

 the more usual case being one slight fall before Christmas, and another 

 some time after, with little permanence of the snow-mantle beyond a week. 



The full range of temperature thus affords occasional examples of 

 Arctic cold, as well as Tropical heat ; but temperate conditions are still the 

 average experience. 



II. Light. More remarkable is the low value of the sunshine record. 

 Less than one-third of total daylight is included as bright sunshine ; the 

 average ' cloud ' ranging very uniformly from 75 % of the time in the winter 

 months (Dec., Jan.) to 63-67 % of the summer months (July, Aug., Sept.), 

 leaving the average hours of bright sunshine as only 1-38 in December to 

 6-42 in June. Yet maximum sunshine may extend to over 15 hours (15-9, 

 June 28, 1921) in fine weather in May, June, and July ; while in the darker 

 months, maximum hours of sunshine may be occasionally 6-7. But in the 

 latter case it must be noted that with a low sun these are but equivalent to 

 the morning and evening hours of the summer, and numbers of hours are by 

 no means a fair measure of the photosynthetic value of the light. The year 

 1921 was conspicuous for the brilliant and long-continued hours of sunshine 

 throughout the dry summer into August, September, and the first half of 

 October. In the two last months the cloud average fell below 50 % 



III. Rainfall. Data for net amount of rain are most readily collected, 

 though the methods adopted are still open to minor errors. Wet weather 

 is on the whole remarkable for its generally even distribution ; a rough 

 working average of one day fine and two days wet, more or less, obtains 

 throughout the year. If no rain falls for a fortnight it begins to be regarded 

 as a drought. The yearly average (70 years, 1851-1920) is just 26 inches 

 (26-022), ranging from 18-056 (in 1902), and the exceptionally dry season of 

 1921 (14-95 i"-) 1 to wet years with 37-712 inches (1903). 



Such records are open to the objection that exceptionally heavy rain 

 for a few days may run up the total without any appreciable effect on the 

 climate as a whole. A maximum of 1-2 inches may fall in one day (2-010 in., 

 June 14, 1903), or \ inch in one thunder-shower. April 25, 1908, is registered 

 as 1-839 in. falling as continuous snow. A heavy rainfall which may rapidly 

 drain away does not necessarily imply a wet year, the distinguishing feature 

 of which will be a small but fairly continuous supply, or a heavier fall than 

 usual in the summer months, associated with much cloud (1873). The 

 monthly average throughout the year runs very uniformly at 2 inches a month 

 (mean for 65 years) ; less in spring months, but more in the summer (2-528 

 July and 2-889 October). In extreme cases 6 inches a month may be 

 exceeded (Oct. 1903, 6-431 in.; Sept. 1896, 6-009 '")> usually with accom- 

 paniment of floods. Half the rainfall comes with a SW. wind. 



1 In the exceptional drought of 1921, beyond one or two severe thunder-showers (Aug. 17). and 

 one wet day in September, there was continuous fine and dry weather from the beginning of February 

 to mid-October. In the meteorological records this appears as rain on 16 days in May and 16 in 

 August ; it being clear that dew is included in many cases as rainfall (even to -ooi in. on some days). 



