Officials at the Environment Agency have blamed the recent heatwave for the deaths of thousands of freshwater fish, across the region.
The intense heat has caused oxygen levels in the water to plunge. There have been reports of fish in distress in Welney in Norfolk and Tiptree in Essex.
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Dry with clear or sunny spells. Winds easing overnight.
Very warm with sunshine. Chance of thundery showers late morning.
A hot, humid and sunny start before cloud increases as a narrow band of thunderstorms spreads northeast. These clear during the afternoon.