Despite appearances, autumn has not arrived early – but more atrocious weather is on the way.

Britain is trapped in a barrage of depressions rolling off the Atlantic, loaded with wind and rain. Conditions will be calmer over the next couple of days, although temperatures will fall so low that there may be ground frost in parts of the Midlands and North tonight.

However, this will be the lull before the next storm. Computer models indicate that another belt of Atlantic depression will arrive on Friday, just in time to ruin the weekend with more wind and rain. With rivers swollen and the ground saturated in places by weeks of heavy downpours, further flooding is possible.

Driving this wretched weather is the jet stream, a river of wind that snakes around the globe a few miles above our heads. Last weekend it developed a kink that trapped a deep depression over Britain. The weather pattern is reminiscent of that which caused heavy flooding in Central Europe in the summer of 2002.

On the other side of the jet stream’s kink, southeastern Europe is roasting in a heatwave. In southern Italy and Greece temperatures have reached 44C (111F), in Romania 19 people have died from the heat and the highest recorded temperature in Bulgaria has been exceeded. Normally at this time of year summer arrives when a block of high pressure from the Azores pushes north and bathes Britain with sunny, dry weather. Although high pressure will try to push into southern England this week, and bring some fine weather to Wimbledon, it will be shoved aside by the expected incoming depression.

Appalling June weather is not unusual. The wettest June of the previous century occured ten years ago, with 133.7mm (5.3in) of rain. Wimbledon was affected so badly that matches were played on the middle Sunday of the championships for just the second time. It was also so cold that snow fell on the Cairngorms on the last day of the month. Although those levels of rainfall are unlikely to be passed this month, the record for the wettest May and June months combined could be challenged.

If it is any consolation, temperatures are holding up surprisingly well. This month will probably be warmer than average, the tenth successive month of above-normal temperatures. But is summer ever going to return?

The weather this year has been trapped in some long, persistent patterns and the next key date to watch out for may be mid-July, when the weather in Britain usually settles into a new pattern – which will make the folklore forecast of 40 days’ rain or drought after St Swithin’s Day, July 15, particularly interesting this year.