NWS / NOAA weather: Extreme Heat Warning issued July 4 at 5:02PM EDT until July 4 at 9:00PM EDT by NWS Baltimore MD/Washington DC

* WHAT...Dangerously hot conditions with heat index values of 110 to
115.

* WHERE...Portions of DC, central, north central, northeast,
northern, and southern Maryland, and central, northern, and
northwest Virginia.

* WHEN...Until 9 PM EDT this evening.

* IMPACTS...Heat related illnesses increase significantly during
extreme heat and high humidity events.

* ADDITIONAL DETAILS...Prolonged excessive heat may impact power,
water, and transportation systems. Heat index values around 100 to
105 are possible again Sunday afternoon.

Source: NWS / NOAA weather.