Weather Watch: As a guide for holiday packing, the world weather figures may be inadequate. Especially for travellers to Bulgaria.

A few months ago, a reader rang this newspaper to ask about the weather somewhere in North Africa. He was about to travel there, and had to decide what clothes to pack. The problem was that the temperatures quoted for the relevant city in our newspaper were almost 20 degrees different from those of some other papers.

After looking into the matter, we discovered that we had printed a temperature close to the minimum for that day, while the other figures quoted had been near the maximum. We therefore advised short-sleeved shirts and warm woolly pyjamas.

Looking at the full figures over the weekend reveals the extent of this problem. While London (minimum 13C, maximum 20C) has the sort of night and day variation one might expect, and Moscow (1C and 3C), Los Angeles (19 and 20) and Bermuda (25 and 29) recognised almost no difference between night and day, the nights may seem very chilly in Oslo (4 and 18), Prague (3 and 17) or Rome (12 and 29).

The Bulgarians, however, have the worst of it. They have no weather at all following the theft of a high-voltage power cable supplying the Meteorological Office in Sofia. With no back-up power supply, the country has no forecast for the first time in 50 years.