NWS / NOAA weather: Extreme Heat Warning issued July 4 at 12:47AM EDT until July 4 at 8:00PM EDT by NWS Baltimore MD/Washington DC

* WHAT...Dangerously hot conditions with heat index values up to 105
to 108 expected.

* WHERE...Portions of north central Maryland, northwest Virginia,
and eastern and panhandle West Virginia.

* WHEN...From 10 AM this morning to 8 PM EDT this evening.

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

* ADDITIONAL DETAILS...Early morning low temperatures in the 70s
combined with oppressive humidity will result in little to no
overnight relief. Prolonged excessive heat may impact power,
water, and transportation systems. Heat index values of 95 to 100
are possible again Sunday afternoon.

Source: NWS / NOAA weather.