However hard it may seem to be raining, you may take comfort in the fact that it is probably not nearly as wet as you think.

As we walk through the pouring rain, having left our umbrellas at home or on the bus again, it is easy to overestimate just how much water is falling on us. There is something about being wet and miserable that makes us feel even wetter and more miserable.

Suppose it is raining steadily - not pouring, or drizzling, just ordinary, common-or-garden or waiting-for-a-bus rain. How much rain do you think would fall in an hour? An inch or two, perhaps? It certainly feels like that, but calculations show that the true figure is nearer to one millimetre. You would need a complete day of steady rain to produce an inch.

Records at Kew show that a fall of more than an inch of rain in a day occurs only about once a year. In a full year, London's total rainfall is about 2ft of water - scarcely enough to swim in.

On the other hand, a really good storm (or a bad one, depending on your point of view) can bring more rain in a day than you might expect in a month, or even a year. The next time you feel like complaining about the rain, take a trip to the parish church at Bruton in Somerset. You will find a plaque there marking the worst ever deluge in Britain, when nearly 10in of rain fell on 28 June 1917. Now that's real rain.