Heat wave sweeps US southwest

Phoenix, Las Vegas, Denver and California's Death Valley have all posted record temperatures as dangerous heat sweeps across the US southwest.

The National Weather Service in Phoenix reported a temperature of 46C, tying the record high for the date set back in 1918.

Las Vegas tied a record for the day set in 1956, with temperatures soaring to 43C on Saturday.

The National Weather Service said there was a chance the high temperatures in both cities could rise even more.

In Colorado, Denver hit 38C, tying a record set in 2013 for both the high temperature and the earliest calendar day to reach 100 Fahrenheit (38C).

Temperatures in several inland areas of California reached a record high for June 11, with 50C recorded in Death Valley.

Excessive heat warnings and heat advisories were issued for parts of Northern California through the Central Valley and down to the southeastern deserts.

The National Weather Service also predicted 46C in Palm Springs and temperatures around 38C across the San Joaquin Valley and the Sacramento area.

Meteorologists warned of very high "heat risk" in south-central Arizona through the weekend.

The high temperatures were likely to approach record-breaking territory -- anywhere between 43C and 46C. They have urged the public to limit outdoor activities.

Heat is part of the normal routine of summertime in the desert, but weather forecasters say that doesn't mean people should feel at ease.

Excessive heat causes more deaths in the US than other weather-related disasters, including hurricanes, floods and tornadoes combined.

Scientists say more frequent and intense heat waves are likely in the future because of climate change and a deepening drought.