Hundreds of people flocked to Hackney Marshes yesterday (June 25) to cool down during the heatwave, ignoring social distancing rules.
The clip, filmed by a passerby, shows people playing loud music while splashing around in the water.
Some revellers even brought along a dinghy.
"They had a sound system and were splashing the water into each other's faces. This river is incredibly dirty!" local citizen and film Kyle told Newsflare.
The BBC reported that Thursday was the hottest day of the year so far, reaching 33.3 degrees Celsius (92F) which surpassed the earlier record from Wednesday at 32.6 (90F).