Concerns over water quality have forced Olympic event delays, including the men's Olympic triathlon that was due to take place on Tuesday after tests on the River Seine deemed it too dirty for swimming.
Organizers are hoping that some sunshine along with scorching temperatures will improve the water conditions so that triathletes can swim in it.
The men's event was rescheduled for Wednesday but will only happen if water tests come back with acceptable levels of E. coli and other bacteria.
Another backup date for both the men's and women's competitions is Friday.
Storms and rain are forecast for Tuesday night through Thursday, which could further delay the competitions and cause complicated rescheduling due to rising bacteria levels from the rain.
"It's disappointing that there's this negative aspect now with the delay," American triathlete Seth Rider told the Associated Press.
"But I hope we can have a triathlon and I can accomplish this dream that I've had since I was a little kid."
France carried out an extensive cleanup effort in the long-polluted waterway ahead of the games
