Parts of Sharjah were hit by heavy hail on Tuesday, with more unstable weather expected across the country.
Footage released by the National Centre of Meteorology showed hail falling in Al Fayah area at about 4pm.
Light rain also fell in Al Ain and over the Dubai-Al Ain road.
The weather forecaster said rain clouds are expected until 9pm, which may bring heavy rain and strong winds.
This will reduce visibility and people are advised not to go near valleys or wadis, NCM said.
Much of the country woke up to heavy fog on Tuesday morning.
Humidity edged close to 90 per cent at 6.30am. High summer temperatures remain and the NCM said the maximum temperature reached 45°C in some areas.
The highest temperature of 46.2°C was recorded in Sweihan, Al Ain at 2:30pm.
Rain clouds will continue to form on Wednesday, and there will be fog on Thursday over some coastal areas.
It is expected to be partly cloudy on Thursday, with the likelihood of mist over some internal areas on Friday.