As intense heat continues to move across the eastern two-thirds of the nation throughout the week, air quality will likely suffer as a result.
The cities plagued most by the heat will be St. Louis, Kansas City, Chicago, D.C. and Philadelphia.
Air quality will deteriorate in these areas, with most of the East and Midwest facing moderate health concern as a result of the air quality.
According to the air quality index at airnow.gov, a moderate health concern means that 'air quality is acceptable; however, for some pollutants there may be a moderate health concern for a very small number of people who are unusually sensitive to air pollution.'
Areas of more serious concern include Atlanta, Pittsburgh, St. Louis, Chicago, Detroit, Cleveland and Cincinnati.
These areas have been temporarily deemed unhealthy for particularly sensitive groups. According to airnow.gov, "Members of sensitive group may experience health effects."
The general public is not likely to be affected, the site explains.
It's not a coincidence that poor air quality usually accompanies heat waves.
"When you get a large area of high pressure promoting widespread heat, you also get a large zone of stagnant air," said AccuWeather.com Meteorologist Meghan Evans.
"Smoke and ozone can be trapped in the atmosphere, leading to poor air quality."
For the full story on the heat, click here.
An intense band of heavy rainfall will continue across South Carolina and far southeastern North Carolina into Monday, worsening the already historic flooding that is underway.
Heavy rain continues to fall over parts of the Carolinas, exacerbating the already historic flooding.
Hurricane Joaquin is barreling down on Bermuda as the weekend comes to an end, posing hazards to residents and vacationers.
According to the BBC, the Brague River overflowed its banks, sending water into nearby towns and cities, including Cannes.
Catastrophic flooding slammed Charleston, South Carolina, and other areas across the state over the weekend.
The 44th Annual Albuquerque International Balloon Fiesta began on Saturday morning, but stormy conditions could cause trouble through Tuesday.
Denver, CO (1969)
9.6 inches of snow fell. October of 1969 would end up being the coldest and snowiest of record for Denver with 31.2 inches of snow for the entire month.
Early season snowstorm claimed 17 lives in Central New York and injured 332. Vermont suffered 17 million dollars in damage. Albany New York received 6 inches of snow which was their earliest measurable snow in 117 years of records.
Heavy thunderstorms and some waterspouts through the southern part of the state. Davie, FL, had 3.57 inches of rain in one hour.