Extreme Heat to Slide East After Baking the West

All About 'Heart Attack' Snow

Portions of the West sweltered in a late-spring heat wave that was one of the sharpest so early in the year for some locations.

The high temperature of 115 degrees at Phoenix, Arizona, on Saturday was their earliest 115 degree temperature on record. Through Monday, Phoenix set four straight daily record highs with temperatures 111 degrees or warmer each day.

In addition to the Desert Southwest, the heat has impacted the Pacific Northwest, Great Basin and Rockies in recent days due to an impressive high-pressure ridge aloft.

Early Week Western Heat

When this pattern occurs, the air sinks and warms, and the result is very few clouds and extremely high temperatures. The highest temperatures of the season have been felt across a large area of the West.

Highs in Seattle topped the 90-degree mark Sunday for the first time this year, with an official high of 93 degrees at Seattle-Tacoma International Airport. Seattle averages only three days of 90-degree-plus heat each year. Last summer, the Emerald City sweltered through a record 12 days of 90s.

The high temperature in Portland, Oregon, maxed out at a daily record of 100 degrees on Sunday.

(MAPS: 10-day High/Low Temperature Maps)

Records Set 

Thursday, Death Valley National Park recorded a high of 120 degrees, topping the daily record, there. This was the nation's first 120-degree high of 2016.

Friday, almost two dozen cities tied or set daily record highs, including:

• Phoenix: 113 degrees
• Las Vegas: 107 degrees (tied)
• Reno, Nevada: 96 degrees
• San Francsico (SFO Int'l Airport): 87 degrees (tied)

Saturday, more records continue to pour in, including:

• Needles, California : 118 degrees
• Phoenix : 115 degrees 
• Las Vegas : 109 degrees (tied)
• Medford, Oregon: 100 degrees
• Portland, Oregon : 98 degrees

• Boise, Idaho: 97 degrees
• Phoenix: 113 degrees
• Tucson, Arizona: 110 degrees
• Las Vegas: 109 degrees
• Yakima, Washington: 101 degrees
• Portland, Oregon: 100 degrees
• Spokane, Washington: 95 degrees
• Grand Canyon Airport: 95 degrees
• Eugene, Oregon: 94 degrees
• Seattle: 93 degrees

Monday's daily record highs:

• Phoenix, Arizona: 111 degrees
• Tucson, Arizona: 111 degrees
• Yakima, Washington: 104 degrees
• Pendleton, Oregon: 100 dgrees
• Salt Lake City: 97 degrees
• Spokane, Washington: 96 degrees
• Missoula, Montana: 94 degrees

(MAP: Actual Highs)

Potential Impacts

This type of heat can be life-threatening for some, especially if you aren't adequately prepared. Remember: heat-related illnesses, such as heat exhaustion and heat stroke, are possible under these extreme conditions. If you are traveling with young children or pets, please do not leave them unattended in a hot vehicle.

The NWS office in Phoenix has issued some great heat safety tips.

• Drink before you are thirsty.
• Reduce time in the sun.
• Avoid strenuous activity; postpone outdoor activities.
• Seek air-conditioned buildings.
• Help the elderly, kids and pets stay cool.
• Keep window blinds closed.

February Record Heat

It was back in February when early-season heat first made an appearance across parts of the Southwest. Dozens of record highs were toppled across the Golden State, Desert Southwest and other parts of the West as many locations rose into the 80s and 90s.

The warmth was a staggering 15 to 25 degrees above average, even warmer than typical highs during the hottest months of the summer.

Phoenix recorded its earliest 90-degree day on record on Feb. 10, more than a full week ahead of the previous earliest occurrence on Feb. 24, 1986 and 1904, according to the NWS.

Death Valley reached the 90-degree mark for the first time this year on Feb. 15, topping a daily record and missing the earliest such "first 90s" of the year by just five days (Feb. 10, 2006). Incidentally, America's hottest location sees more days with highs in the 90s or above each year (193 days) than days below 90 degrees (172).

MORE ON WEATHER.COM: Southwest Heat Wave, July 2, 2013