May 6, 2024 - Climate

Hotter, drier summer looms for most of Oregon

Illustration of a thermometer shaped like an upwards arrow, with the mercury rising.

Illustration: Brendan Lynch/Axios

It's shaping up to be a hotter-than-usual summer for the majority of Oregon, according to new forecasts and research.

Why it matters: Nearly 70% of Portlanders live on heat islands — parts of the city that are hotter and more dangerous than others on very warm days — per a 2023 data analysis by nonprofit climate research group Climate Central.

Flashback: A historic heat dome phenomenon in 2021 brought a 116-degree day to Portland, breaking all-time records, and was linked to 69 deaths in Multnomah County.

Driving the news: A recently released climate outlook from the National Oceanic and Atmospheric Administration for July through September shows the chances for hotter-than-average conditions are highest across a swath of land that includes Texas, the Rockies and the Pacific Northwest, as well as the Northeast.

  • The West is also projected to see below-average rainfall following a warmer-than-average spring, which could raise wildfire risks.

The intrigue: One wild card this summer will be exactly where persistent areas of high pressure, also known as heat domes, set up. That will determine the areas that see some of the hottest conditions.

Threat level: Nearly 37% of Oregon is experiencing "abnormally dry" conditions, and roughly 5% is in moderate drought, per NOAA.

  • This includes central parts of the state like Deschutes, Lake and Klamath counties — where large wildfires have taken place in the past.

What they're saying: "If the outlook for a hot and dry spring and summer materialize, we expect higher wildfire risk than normal, particularly in the Coast Range and Cascade foothills," Larry O'Neill, Oregon's state climatologist, told Axios via email.

  • And while the recent bout of rain has helped, it "does not appear to be enough to restore the soil moisture deficits that have developed over the last 6-8 weeks," he wrote.

What we're watching: While hot and dry conditions amplify the risk of wildfire, human-caused fires are the biggest challenge the Oregon Department of Forestry faces, spokesperson Jessica Neujahr said.

  • Last year, over 80% of fires on ODF-protected lands were human caused, where a single spark can lead to huge spread, she added.

What's next: The National Weather Service and the Centers for Disease Control and Prevention rolled out an experimental heat forecast tool that can give health guidance up to seven days in advance.


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