By Philip Eden

There could hardly have been a bigger contrast in weather from one week to the next. The early-July heatwave ended on the 7th and since then the weather has been in typical British high summer mood: cool, cloudy, showery, and blustery.

The numbers confirm the sharp contrast between the two weeks. In at Manchester the first week of July had a mean maximum tempe rature of 26C and the sun shone for 53 hours, while the equivalent figures for the second week were 17C and 25 hours. Norwich recorded 61 hours of sunshine between July 1 and 7, and just 20 hours during the following seven days. There were large geographi cal variations in rainfall during both weeks, but near Cheltenham 2mm of rain during the first week contrasted with 90mm during the second.

Chilly, unsettled weather is not unusual in July. Ours is a maritime climate and is characteristed in all seasons by depressions and their attendant frontal systems advancing across the country from the Atlantic Ocean. Spells of fine, settled weather do o ccur from time to time, but however long they last we should remember that they are the exception rather than the rule.

If there is such a thing as a typical July we should expect it to provide us with two or three short fine spells, often lasting no more than three or four days, set against a background of changeable westerly winds with variable skies and occasional burst s of rain. Even the hottest and sunniest Julys - 1995, 1994 and 1976 for example - have brief interruptions when the temperature drops to the seasonal norm and the sun disappears. The July of 1911 was the only one during the 20th century which could legit imately be described as dry and sunny throughout, although even that was only true in the southern half of the UK.

Equally rarely, July may be relentlessly cool and cloudy and rainy; July 1988 was one of the best examples. In London the temperature failed to exceed 22C any day that month, at Plymouth and on Guernsey the monthly maximum was a mere 18.3C, while at Land' s End the mercury stayed below 16C on every single day.