DIRE predictions of a lethal heatwave need their own health warning. It is far too early to say what sort of summer we can expect.

The Met Office’s seasonal forecasters are pointing to above average temperatures next month and in July and August, but what does this mean? It tells you nothing about when the warmth will come; days could be mild and nights unusually warm. Averages iron out details necessary to plan a barbecue.

Long-range forecasts have to be vague. Forecasting next week is difficult enough, so trying to make detailed predictions months ahead lies in the realms of Mystic Meg.

The Met Office’s seasonal forecasts rely heavily on the temperatures of the oceans, which cover 70 per cent of the world’s surface and form a huge part of the global climate. They soak up vast amounts of heat — the top 3m (10ft) of the oceans contain more heat than the entire Earth’s atmosphere.

However, unlike the atmosphere, this heat is released slowly like a colossal storage heater. In the North Atlantic the stored heat pumped into the atmosphere is equivalent to a million power stations, keeping Britain remarkably mild in winter; however, the turbulent and shifting changes in the atmosphere make our weather from day-to-day incredibly varied.

So, for the UK, information about the North Atlantic should indicate wetter or drier and warmer or colder seasons. Satellites give a broad picture, but a network of robotic buoys is being installed across the seas to give more detailed observations, and provide better seasonal forecasts.

The history of more detailed long-range forecasts is littered with bruised egos as confident predictions are proved false. What we can say for sure is that the British summer is growing warmer all the time.

Explore UK News

• Crime News

• Education News

• Health News

• Scotland News

Times Recommends

• UK regional accents thrive against the odds
• ‘Scarecrow’ wind farms put rare birds to flight
• What an anti-climax: G-spot is a myth