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Massive heat wave continues through weekend
01:45 - Source: CNN
CNN  — 

The roughly 4,000 athletes who trained for Sunday’s New York City Triathlon will have to wait for another event – thanks to this weekend’s major heat wave that’s scorching much of the United States.

The 19th annual endurance race in Manhattan is canceled, organizers said Thursday, with temperatures and humidity expected to be beyond safe racing conditions.

Racers will be refunded their registration fees automatically in two to three weeks, organizers said.

Track the extreme heat

“After exhausting all options to mitigate athlete, volunteer, spectator and staff exposure alike, we are unable to provide either a safe event experience or an alternate race weekend,” organizers said.

Sunday’s high temperature in New York is expected to be in the mid-90s Fahrenheit – but humidity will make it feel like 105-110 degrees, forecasters say.

The race would have begun at 5:50 a.m., before the day’s high temperature, but organizers said conditions throughout the morning still will be too hot and humid. The National Weather Service has put New York City under an excessive heat warning from noon Friday until 8 p.m. Sunday.

That kind of warning is issued when the combination of heat and humidity is expected to make it feel like it is 105 degrees or more. New York City Mayor Bil de Blasio declared an emergency for the city from Friday to Sunday evening, ordering certain tall office buildings to have their thermostats set at no lower than 78 degrees, to reduce strain on the electrical grid.

A sports and fitness expo associated with the triathlon still will be open Friday and Saturday at the Hilton Midtown hotel, organizers said.

The race – drawing registrants from 33 countries and 45 US states – would have had participants swimming 1,500 meters in the Hudson River before cycling 40 kilometers and running 10 kilometers in Manhattan.

The heat wave is canceling other sporting events around the nation, including horse races in New York state and Maryland.

CNN’s Rob Frehse contributed to this report.