Northern Ireland was hit by flooding with double the average rainfall
Last month was the dullest August in the UK since records began in 1929, the Met Office has confirmed.
There were just 105.5 hours of sunshine, far less than the average for the month of 165.1 hours.
This August was also the fifth wettest on record with 139.8mm (5.5in) of rain falling, causing floods in some areas.
But John Hammond, from the Met Office, said forecasters expected autumn temperatures to be above average while rainfall would be below average.
The Met Office said high pressure around the Azores which usually brings warmer, brighter weather to Britain in the summer simply had not materialised this year.
But things have not been all bad. In Shanklin, on the Isle of Wight, sunshine levels were 130% of the average.
At the opposite end of the country, in Lerwick in Shetland, the sunshine level was 129% of what forecasters might expect.
And Mr Hammond said things were looking up for the coming months.
"For autumn, we are very much expecting temperatures to be above average and for the season itself to have below average rainfall," he said.
Northern Ireland was hit by flooding in August, after receiving double the average rainfall for the month.