According to Met Office reports, temperatures were above 30ºC at a number of weather stations for a period of ten consecutive days, beginning a day earlier than the increase in deaths.

ONS estimates that the number of deaths peaked at 1,691 on Monday 11 August 2003, the day after peak temperatures were recorded. This was 363 more deaths than the average for that day over the previous five years

In London, the East of England and the South East there were 6,044 deaths in the ten days from Monday 4 August to Wednesday 13 August, 40 per cent of the national total. This was 1,314 above the average for the same period in the previous five years and 64 per cent of the increase nationally. Over most of these regions, temperatures exceeded 30ºC on 10 August.

In August as a whole, there were estimated to be 1,495 deaths above the average for that month over the last five years. This contrasts with July, where deaths were 746 below the July average over the last five years.

Although numbers of deaths in August 2003 were higher than average, the peak number on 11 August was still lower than typical daily mortality in the winter months. Over the last five years, December and January had daily averages of 1,725 and 1,872 deaths respectively. Average daily mortality in August (1,362 deaths) was also lower than average daily mortality over the whole of the previous five years (1,485 deaths).