Heatwave simmers the U.S. Pacific Northwest

Temperatures soared on Sunday to an all-time high of 112 degrees Fahrenheit in Oregon's largest city as a record heat wave blistered the Pacific Northwest, sparking a run on ice and air-conditioners, while forcing many restaurants and bars to close.

Jayson Albano reports.

An unprecedented heatwave has hit the U.S. Pacific Northwest.

It's causing some bars and restaurants to close and sent many flocking to the nearest pool on Sunday.

In the usually-temperate states of Washington and Oregon, homes and businesses have long gone without air conditioning.

But the National Weather Service forecasted high temperatures, climbing to more than 30 degrees above normal in parts of those states.

Seattle, Washington on Sunday saw temperatures reach an all-time high of 104 degrees Fahrenheit, or 40 degrees Celsius.

In Portland, Oregon, temperatures also soared to an eye-watering 112 degrees Fahrenheit.

According to the NWS that's the hottest temperature since records began in 1940.

The extreme heat was said to be caused by a dome of atmospheric high pressure over the upper U.S. northwest and Canada.

That's similar to conditions that punished California and southwestern states a week earlier.

"When we travelled from Oakland, California there was supposed to be a heat wave (there).

The four of us, we thought because Portland is in the North West it would be nice and cool, and we get here and it is so hot, and the weather back at home is nice and cool." Oregon Governor Kate Brown eased restrictions for swimming pools, theatres and shopping malls ahead of the heatwave.

Meanwhile stores there quickly sold out of air conditioning units, fans - even ice.

Multnomah County - which contains the city of Portland - opened emergency 'cooling shelters', most of them in public libraries for residents without AC units to escape the searing heat.

The NWS says the heat wave is expected to ease somewhat by Tuesday.