Climate Minute: Pacific Northwest Heat Wave

High temperatures to trend twenty to forty degrees above-average

Kaiti Blake joins GMSA@9 to discuss the latest heat wave in the Pacific Northwest in this week's Climate Minute.

SAN ANTONIO – The Pacific Northwest - including major cities like Seattle and Portland - is facing a historic heat wave through early next week. High temperatures from southern Oregon to northern Washington will approach and exceed one hundred degrees on Saturday, Sunday, and Monday.

High temperatures in many locations across the Pacific Northwest will exceed one hundred degrees over the weekend of June 26, 2021. Seen in the image above are forecast high temperatures for Sunday, June 27, 2021. (Copyright 2021 by KSAT - All rights reserved.)

While one hundred degrees might not seem too extreme to most Texans, temperatures like that are quite significant and out of the ordinary for the Pacific Northwest. The average high temperatures in Seattle and Portland this time of year are around seventy-four and seventy-six degrees, respectively. During this heatwave, they’ll be some twenty-five to forty degrees higher than that.

How does this affect you? Watch the video above from Meteorologist Kaiti Blake to learn more about how this heat wave ties in to our South Texas climate

In terms of meteorology, the extreme heat is due to a strong area of high pressure sitting over the region. However, on a larger scale, these types of heat waves are expected to become more common in the coming decades. The reason? A warming global climate that will result in more extremes in day-to-day weather, like heat waves. This is true not only for the Pacific Northwest, but for areas all over the globe.

There is evidence of this warming climate in just the last thirty years. The image below from Climate Central illustrates how the Seattle area has seen an increase in ‘hot days’ over the last thirty years. A ‘hot day’ is a day above eighty-five degrees, which is above average for the Seattle area - even during the hottest time of year. (For comparison, San Antonio’s ‘hot day’ threshold is one hundred degrees.)

According to Climate Central, there has been an eight-day increase in the number of hot days over the last thirty years in the Seattle area (Copyright 2021 by KSAT - All rights reserved.)

For more climate-related stories - including more Climate Minute segments - go to’s Climate page.

About the Author:

Kaiti Blake is a child weather-geek-turned-meteorologist. A member of the KSAT Weather Authority, Kaiti is a co-host of the Whatever the Weather video podcast. After graduating from Texas Tech University, Kaiti worked at WJTV 12 in Jackson, Mississippi and KTAB in Abilene.