Well the answer is quite a lot. Sales of ice cream are very closely linked to temperatures and sunshine. The warmer the weather the more we tend to buy.

So if organisations such as the Met Office can predict the trends in temperatures over the following few weeks or months, then ice cream manufacturers can anticipate the likely demand for their products and increase or decrease production accordingly.

Ice cream is a fairly obvious example - but it is not always so simple. Take fizzy drinks for example. As the temperature rises the demand for these drinks increases. But above about 23 or 24 degrees Celsius people turn away from these drinks and instead they look to bottled water to quench their thirst.

Anticipating the demand for products in supermarkets has become much more sophisticated than merely stocking more salads in hot weather. Most cat owners will tell you that their ‘moggies’ eat less food in warm weather. So rather than tell the petfood manufacturers when the weather is going to be, we can now tell them what the demand for catfood will be.

This link between weather and maunfacturing can be a highly profitable one, but it doesn’t work all the time. Grass grows faster in warmer weather, so you might think that the demand for lawnmowers would increase.

But that’s not the case. After a winter in a damp garden shed most of us either buy a new mower at the start of the season when the old one doesn’t work, or - like me - they soldier on with old one.