A teen who drowned in the Rangitikei River ignored warnings that the water wasn't swimmable.

Police have recovered a body after a 16-year-old went missing on Sunday.

Horizons Regional Council had flagged the spot he disappeared from as a no-go-zone because of E.coli.

About 40 per cent of popular swimming spots in the region have E.Coli readings that make them a potential health hazard or unsuitable for swimming and Horizons Regional Council is urging people to think before they swim, even though it's scorching hot.

Council science and innovation manager Abby Matthews says the drowning is a tragedy and it's disappointing more spots aren't swimmable.

"We do have safety messages on signs at a lot of our spots, and certainly our website is a good place to check. The E.Coli itself is usually a really good indicator that the flows are a little nit higher at most sites.