The continued hot weather has led the Met Office to issue another warning for much of the UK, including Northamptonshire.
The forecasters say the hot weather could spark scattered thunderstorms later on today (Thursday), continuing overnight.
Spray and sudden flooding could lead to difficult driving conditions and some road closures, and where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services.
There is a chance that power cuts could occur and other services to some homes and businesses could be lost, and even a small chance that homes and businesses could be flooded, or damaged by lightning strikes, hail or sudden gusts of wind.
The BBC weather forecast for today predicts temperatures will peak at 35c between 3pm and 5pm, and won't fall far below 20c throughout the night.
It says 1am is the most likely time for thunderstorms and rain to break out in this county.