US cities face record high temperatures on worst day of heat wave

(Reuters) -Tens of millions of people in major cities across the U.S. Northeast are facing record high temperatures on Tuesday on what was expected to be the worst day of an oppressive heat wave that has spread over much of the country since late last week.

Temperatures in Washington and Boston are expected to soar to 101 degrees Fahrenheit (38 Celsius), beating previous records by as much as 6 degrees, according to the National Weather Service.

In New York City's Central Park, temperatures could reach 99 F (37 C), surpassing the area's past high of 96. There is also the potential for record heat across other parts of the Eastern U.S., including northern Georgia, the Carolinas, Virginia, Maryland and Pennsylvania, according to the NWS.

"It looks like today is probably the worst day for widespread heat records," said Bob Oravec, lead forecaster at the National Weather Service in College Park, Maryland, adding that the most intense heat is concentrated in the Northeast.

The extreme heat is causing disruptions to public transport across the Northeast, with U.S. passenger railroad Amtrak saying it will be forced to slow train speeds between 12 p.m. and 8 p.m. on Tuesday between Washington and New York and between Philadelphia and Harrisburg, which could lead to delays.

Construction companies have been forced to compensate for the severe weather to ensure their construction workers are safe. Jeff Wagner, communications manager at construction firm Fluor, said the company was providing cooling stations and heavy-duty water bottles to its more than 2,000 laborers working on a pharmaceuticals project in Indiana.

"We have safety meetings every morning, but knowing this was going to be an exceptionally hot week, (we spoke about) hydration and making sure workers are pacing themselves," said Wagner.

In New York City, residents hoping to cast their votes in primary elections have been compelled to endure the soaring temperatures. Accountant Alex Antzoulatis, 53, who turned up at a poll site in Astoria, New York, on Tuesday to cast his ballot in the mayoral primary, told Reuters he regretted not voting by mail.

He said he went to the poll site in the 100-F heat only because he sees voting as his duty, "but the heat will keep a lot of people away".

The warm weather across the U.S. Plains and into Canada has also impacted crops. In Saskatchewan in Western Canada, where much of the country’s canola, spring wheat and pulse crops are grown, dryness in June hindered just-seeded crops.

Rainfall in recent days came too late, said Yorkton, Saskatchewan farmer Bill Prybylski, adding that the damage was partly mitigated by the smoky air from wildfires, which stopped direct sunlight scorching crops.

Oravec at the NWS said temperatures should start to fall on Wednesday. "Like Thursday's temperature high in New York is forecast to be 84 Fahrenheit, and is supposed to be 75 F on Friday."

(Reporting by Patrick Wingrove; Additional reporting by Maria Tsvetkova in New York, Ed White in Winnipeg, and Heather Schlitz in Chicago; Editing by Sandra Maler)