Dangerous heat blankets Maryland on July 4th weekend

The National Weather Service has issued Extreme Heat Warnings and Heat Advisories across all of Maryland Friday as temperatures are expected to reach 97 to 102 degrees with heat index values — what the air actually feels like on the skin — climbing as high as 113 degrees in some areas.

What’s happening: The Baltimore/Washington forecast office issued the alerts at 4:50 a.m. Friday. Heat index values are forecast to hit 110 to 113 degrees in the Baltimore and Washington suburbs, with some areas of Central Maryland approaching 113 degrees.

What’s important: An Extreme Heat Warning is the highest level of heat alert the National Weather Service issues. It means dangerously hot conditions are expected and that heat illness — including heat stroke, which can be fatal — is possible for anyone spending time outdoors, not just those in sensitive groups.

Air quality: The Maryland Department of the Environment issued Code Orange Air Quality Alerts Friday for most of the state, including:

• Southern Maryland, covering Charles, St. Mary’s and Calvert counties.
• The Baltimore City metro area and Annapolis region, covering southern Baltimore and Anne Arundel County.
• Northeast Maryland, covering Cecil and southeast Harford counties.
• The suburban Washington region, covering Prince George’s County and parts of Montgomery and Howard counties.
• The Upper Eastern Shore, covering Kent, Queen Anne’s, Talbot and Caroline counties.

A Code Orange alert means air pollution may reach levels that are unhealthy for sensitive groups, including children, the elderly, and people with asthma, heart disease or other lung conditions. The alerts expire at midnight Friday.

How this affects real people: Health officials recommend avoiding strenuous outdoor activity during Code Orange conditions. The National Weather Service advises checking weather.gov/heat for heat safety information.

What’s next: The National Weather Service says the risk of strong to severe thunderstorms increases Saturday and Sunday.