Experts are predicting a stormy end to the mini-heatwave in parts of Northamptonshire.
Temperatures look set to touch 30°C today (Tuesday) and tomorrow but the Met Office has issued a yellow weather warning for heavy showers and thunderstorms hitting the north-west of the county on Thursday with the risk of flooding in a few places.
The warning is current set for 11am through to 8pm and a Met Office spokesman said: "Following overnight rain and showers, more intense showers and thunderstorms are expected to break out fairly widely from late-morning, before easing during the evening.
"Whilst most areas will miss the most intense storms, torrential downpours are possible in a few places.
"Where these occur, there is potential for 20 to 30mm of rain in less than an hour and up to 40mm in two hours. This would have the potential to generate surface water flooding, especially if it falls over an urban area."
The warning currently covers an area along a line from Rothwell to Daventry, but experts say it could be updated before Thursday.
Meteorologists say there is a small chance that homes and businesses could be flooded quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds Spray and sudden flooding could lead to difficult driving conditions and some road closures.
Local forecasters @NNweather expect two days of dry, hot and sunny in the county today and tomorrow.
Northamptonshire's record high temperature recorded during September at the Met Office Pitsford weather station was 30.1°C September 13, 2016