The warning comes into effect at 10am on Thursday, June 23 and will remain in place until midnight on the same day.
The Met Office website says that thunderstorms are likely to break out in areas across the country. These torrential downpours may be accompanied by frequent lightning, gusty winds and hail.
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.
Travel may also be disrupted during the storms – with possible delays to train and bus services, as well as difficult driving conditions and potential road closures.
The outlook for Friday to Sunday is cloudier with fresher winds and scattered showers, occasionally heavy and prolonged. Feeling a little less warm by the weekend.