Only 59 days until Christmas? It must be time for a barbecue

It was billed as the "barbecue summer" but in reality brought nothing but rain. After July's string of false promises, the Met Office has put its reputation back on the line, heralding this week as the "official Indian summer".

Forecasters at the weather centre have predicted that temperatures will peak at 70F (21C) in the South East and the Midlands on Thursday, compared to the usual highs of 5F (11C) during the last week of October.

The warm weather is thought to be due to southerly winds blowing hot air from the Mediterranean up to the UK. "I think we can now say that it's an official Indian summer. The pleasant weather is perfectly timed for half-term when there will be many families out and about," said John Hammond, forecaster at the Met Office.

"Temperatures will peak on Thursday in South East England, East Anglia and possibly the north Midlands. Sheltered areas between Bristol and London are where it is likely to be warmest – possibly hitting 21C."

Hotels are reporting a scramble for bookings, with many owners – who were left badly bruised by the lack of sunshine earlier in the year – expecting a pleasantly busy week. Warm weather is expected to last until the end of Friday evening or Saturday, with a band of rain moving in across the country.

But, as usual, expectations must be managed. "It won't be perfect all the time – there will be bands of cloud from time to time and also some outbreaks of rain in north and north-western parts of the UK," said Mr Hammond. "But night-time average temperatures are also in double figures due to the warm air, and close to the average daytime maximum."

Some believe that, should all go to plan, the highest autumn temperatures could even break records. These stands at 71F (21.7C) at Prestatyn, north Wales, recorded on 4 November 1946. The highest temperature for late October was 73F at Aber, north Wales on 23 October 1996. But before booking a last-minute holiday, some might want to study similar predictions made last year. In February, the Met Office was forced to concede that it got it wrong over a seasonal forecast issued for September 2008, which predicted that the coming winter would be milder than average.

It was only the fourth time the office had gone public with its winter forecasts, and although the previous three predictions were fairly accurate, this one was, in the words of one spokesman, "wide of the mark".