The National Weather Service predicts mostly sunny skies and calm breezes for St. Louis with highs around 90 degrees, turning partly cloudy with slight chances of thunderstorms and warmer temperatures in the following days.

The NWS predicts steady weather in Knoxville with chances of showers and thunderstorms, mostly sunny days, calm winds, and temperatures in the high-80s.

Alameda County has successfully eradicated a Mediterranean fruit fly infestation, lifting a quarantine after collaborative efforts using sterile male flies and organic treatments.

An air quality alert is issued in Chicago due to Canadian wildfire smoke and high ozone levels, prompting health precautions for those with respiratory issues.

The LAFD offers advice on its website for Los Angeles residents to stay safe during a heatwave, with tips on clothing, home cooling, hydration, and monitoring the vulnerable.

Canadian wildfires cause poor air quality in New York City, with the city ranking ninth-worst globally and impacting regions from the Great Lakes to Maine.

Austin faces a week of intense heat with highs potentially reaching 98 degrees and heat index values up to 104. The National Weather Service advises caution.

Former Tropical Cyclone Gil's remnants are forecast to affect Hawaii, bringing decreased winds, higher humidity, and increased showers. A High Surf Advisory is in effect for south shores.

Seattle's National Weather Service forecasts a partly sunny, 77-degree day with light winds and a 60% chance of rain after 2 AM. Showers and possible thunderstorms expected Wednesday.

The Bay Area faces a heatwave with mid to upper 90s, and a Moderate HeatRisk warning issued for the East Bay and southern Santa Clara Valley. Health officials urge precautions for heat-sensitive groups.

Las Vegas faces an Extreme Heat Warning due to high temperatures and smoke from California wildfires. A Red Flag Warning is in place due to dry conditions. Aviation may be affected, with Harry Reid Airport expecting gusts and high temperatures.

The NWS issued an "Extreme Heat Warning" for Southern California, with temperatures up to 118 degrees expected, and risks of poor air quality due to nearby fires.

Portland's weather will vary, with sunshine today and potential showers tonight and Wednesday morning, followed by clearing skies on Thursday. The weekend promises heat with highs up to 97°F.