The city is advising caution at one of its beaches due to high E. coli levels in the water.

On its website Sunday, the city said E. coli levels at Centre Island Beach "exceed" acceptable water quality standards.

The latest results, which are based on a sample collected on Aug. 16, show an E. Coli count of 176 per 100 millilitres of water. The city's established beach water quality standard is 100 E.coli per 100 ml of water.

While none of the other beaches in Toronto have been flagged for high E. coli, the latest samples were collected a day before the heavy downpour Toronto saw Saturday.

Water quality at the city's beaches has been known to deteriorate after a heavy storm and Saturday's deluge dumped more than 100 mm of rain on some parts of the city.

"Swimming is not recommended during and after storms, floods, or heavy rainfall," the city says on its website.

While the city is seeing hot and muggy weather Sunday – a high of 25 C, feeling like 33 with the humidity – the Toronto and Region Conservation Authority (TRCA) is also advising people to refrain from recreational activity around waterways, as many have swelled from the downpour.

Toronto remains under a rainfall warning as well, with 20-40 mm more expected sometime today.