ABSTRACT
The tapering peninsula of south-west England, with sea on three sides, enjoys the highest annual mean daily temperatures in the British Isles. Not surprisingly, then, the sobriquet ‘English Riviera’ is often applied to the area in general and the sheltered shores of Torbay in particular. Cornwall is the most southerly county of Britain and the most westerly of England, and as a consequence it is subjected to maritime influences, but is also the most exposed and windy in England. While the mean winter temperatures on the southern coasts of Devon and Cornwall compare very favourably with stations on the northern shore of the Mediterranean there is much less sunshine and it rains on a greater number of days on average. The maritime nature of the climate, however, ensures an equability that is perhaps best expressed in terms of the annual temperature range or difference between the mean temperatures of the warmest and coldest months, which in west Cornwall is about 9 degrees C, a similar figure to that found along the western coast of Ireland and in the Outer Hebrides but one which contrasts with the 14 degrees C that characterises Midlands sites, where continentality is much greater. While a general climatic gradient exists across the region from south-west to north-east it is of far smaller significance than the more local climatic contrasts that are found between the exposed, mostly treeless uplands of Dartmoor and Bodmin Moor and the sheltered areas in the surrounding vales. A series of separated upland areas, which include the highest ground to be found in southern England (621 m on Dartmoor on the high ground around Yes Tor), run down the length of the peninsula, and their elevation, coupled with their proximity to the western seaboard, is conducive to producing a more rigorous climate than at lower altitudes: wetter, cooler and more windswept. Thus, while average annual rainfall over most of lowland Devon is not much above 1,000 mm, it is more than double this figure over the higher parts of Dartmoor. While the deeply cut river valleys, like that of the Tamar and coastal ‘rias’ of south Devon and south Cornwall, offer shelter, grass growth is almost continuous in the mild, moist winters, though the uplands are bleak and exposed. The scenic contrasts in Devon and their relation to weather and climate have intrigued several climatologists (e.g. Bonacina 1951; Manley 1952), and some amateur weather observers from an earlier era (Shapter 1862). Daphne du Maurier's (1967) keen observation on the climate of this most south-westerly extremity of the British Isles would pass unchallenged by most climatologists when she states, concerning the change of weather from place to place, ‘this difference in temperature, this vagary of weather, varies from mile to mile with a kind of lunatic perversity’. Location of weather stations and places referred to in the text https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780203437926/3f084266-fdcf-4667-bbe1-28e8fb23aad0/content/fig2_1_B.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>
