LOS ANGELES, July 11 (AFP) - Millions of people across the western United States and Canada were hit on Sunday (Jul 11) by a new round of scorching hot temperatures, with some roads closed, train traffic limited and new evacuations ordered.

In Canada, with wildfires continuing to spread - including 50 more blazes erupting in the past two days - the government announced new emergency measures aimed at preventing further fires.

Sweltering conditions hit much of the Pacific seaboard and as far inland as the western edge of the Rocky Mountains over the weekend.

"A dangerous heat wave will affect much of the western US, with record-breaking temperatures likely," the National Weather service said on its website Sunday, while Canadian meteorologists predicted highs approaching 90 degrees Fahrenheit (32 degrees Celsius) in parts of western Canada - well above seasonal norms.

Las Vegas on Saturday matched its all-time record of 117 degrees Fahrenheit, according to the National Weather Service (NWS) - a temperature recorded in the desert entertainment city once in 1942 and three other times since 2005.

Sunday was expected to be only a few degrees cooler there, while Death Valley, California - often the nation's hottest spot - was headed for a high of 126 degrees Fahrenheit.

Forecasters issued an excessive heat warning for several other urban centers including the southern city of Phoenix and San Jose, the center of the Silicon Valley tech industry south of San Francisco.

The weekend's hot weather follows an earlier heat wave that struck the western United States and Canada at the end of June.

The scorching conditions saw the all-time record daily temperature broken three days in a row in the Canadian province of British Columbia.