Sign up for our daily briefing

Make your busy days simpler with Axios AM/PM. Catch up on what's new and why it matters in just 5 minutes.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on the day's biggest business stories

Subscribe to Axios Closer for insights into the day’s business news and trends and why they matter

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Stay on top of the latest market trends

Subscribe to Axios Markets for the latest market trends and economic insights. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Sports news worthy of your time

Binge on the stats and stories that drive the sports world with Axios Sports. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Tech news worthy of your time

Get our smart take on technology from the Valley and D.C. with Axios Login. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Get the inside stories

Get an insider's guide to the new White House with Axios Sneak Peek. Sign up for free.

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Catch up on coronavirus stories and special reports, curated by Mike Allen everyday

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Denver news?

Get a daily digest of the most important stories affecting your hometown with Axios Denver

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Des Moines news?

Get a daily digest of the most important stories affecting your hometown with Axios Des Moines

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Twin Cities news?

Get a daily digest of the most important stories affecting your hometown with Axios Twin Cities

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Tampa Bay news?

Get a daily digest of the most important stories affecting your hometown with Axios Tampa Bay

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Want a daily digest of the top Charlotte news?

Get a daily digest of the most important stories affecting your hometown with Axios Charlotte

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Sign up for Axios NW Arkansas

Stay up-to-date on the most important and interesting stories affecting NW Arkansas, authored by local reporters

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Please enter a valid email.

Please enter a valid email.

Subscription failed
Thank you for subscribing!

Computer model projection of forecast high temperatures for Wednesday. (WeatherBell)

Heat warnings and advisories are in effect for at least two dozen states through the end of the week. 25 million people are projected to see highs reach or eclipse 100 degrees Fahrenheit this week, as yet another powerful heat dome-dominated weather pattern affects a huge swath of the country.

Why it matters: The heat wave will combine with drought conditions in the Pacific Northwest to aggravate an already dire wildfire situation and bring more miserable weather to residents of Portland, Oregon, and other states hit hard by record-shattering heat in late June and early July.

  • This time around, heat and high humidity will combine to make for dangerously hot conditions in the Mid-Atlantic and Central states, too.
  • The hot and dry weather will only worsen the ongoing wildfires and potentially lead to new ignitions from thunderstorms. California's Dixie Fire, the second-largest blaze in state history and the largest ongoing wildfire in the U.S., grew further overnight toward the 500,000-acre mark, threatening more homes.

By the numbers: A strong area of high pressure across the Pacific Northwest, also known as a "heat dome," will ratchet up the heat from Northern California to Washington state from Wednesday through Saturday in particular.

  • High temperatures of up to 112 degrees are possible in inland valleys in western Oregon, the National Weather Service predicts, with little overnight relief in many areas.
  • High temperatures will generally be from 10 to 15 degrees above average for this time of year.

Threat level: When it comes to fire weather, the Weather Service forecast office in Medford, Oregon, is warning of "excessively hot, very unstable and dry air" across southern Oregon and Northern California — where the Bootleg Fire is still burning, in addition to the Dixie and other blazes.

  • Fire weather warnings for potentially extreme wildfire behavior, including the formation of pyrocumulus clouds, go into effect Wednesday.
  • Portland, Oregon, which set an all-time high temperature record of 116 degrees back in July, is predicted to reach a sizzling 104 degrees Thursday.
  • Meanwhile, in the Eastern U.S., highs in the mid-to-upper 90s will affect the urban corridor between Washington and Boston, with scorching heat even reaching parts of New Hampshire and Maine.

Context: The heat wave comes just a day after a landmark climate science report was released by the UN Intergovernmental Panel on Climate Change (IPCC), which definitively linked the increasing frequency and severity of heat waves to human emissions of greenhouse gases.

  • The report described this connection as "established fact," a striking increase in confidence level since its last major assessment, which is the equivalent of a CT scan for the planet, in 2013.
  • At the same time as the U.S. is feeling the heat and seeing more than 105 large wildfires burn across the country, a brutal heat wave in the Mediterranean region is continuing to fuel deadly blazes in Greece and Turkey.

Go deeper

Biden's extreme weather message: code red

President Biden tours a neighborhood today in Manville, New Jersey, that was hit by the remnants of Ida. Photo: Mandel Ngan/AFP via Getty Images

President Biden demonstrated during visits Tuesday to flood-ravaged New Jersey and New York that he's keen to link recent extreme weather events with calls to tackle climate change.

Why it matters: It could convince more resistant audiences about the seriousness of global warming and also fuel the case for some of those major infrastructure investments Democrats have been promoting.

Biden on extreme weather: "This is code red"

President Biden surveys damage from Hurricane Ida in Manville, New Jersey. Photo: Madnel Ngan/AFP via Getty Images

President Biden said climate change and increasing extreme weather are a "code red," while surveying Hurricane Ida's devastation in New York and New Jersey on Tuesday.

Why it matters: Ida left more than 60 dead and caused "double-digit billion economic damage toll" in the Mid-Atlantic and Northeast according to a report from insurance broker Aon, showing the increasing impact of human-caused climate change.

10 hours ago - Health

FDA advisory panel recommends Pfizer boosters for those 65 and older

A healthcare worker prepares a dose of the Pfizer-BioNTech Covid-19 vaccine at the Key Biscayne Community Center on Aug. 24, 2021. Photo: Eva Marie Uzcategui/Bloomberg via Getty Images

A key Food and Drug Administration advisory panel on Friday overwhelmingly voted against recommending Pfizer vaccine booster shots for younger Americans, but unanimously recommended approving the third shots for individuals 65 and older, as well as those at high-risk of severe COVID-19.

Why it matters: While the votes are non-binding, and the FDA must still make a final decision, Friday's move pours cold water on the Biden administration's plan to begin administering boosters to most individuals who received the Pfizer vaccine later this month.