The heat caused delays on Metro's Red Line Tuesday afternoon.
Trains are single-tracking between Takoma Park and Forest Glen due to a heat kink. That's when the heat causes metal on the tracks to expand. Riders should expect 15-minute delays in both directions.
Heat advisories have been issued from Texas to the Northeast, as half the country braces for a major heat wave.
Here in the D.C. metro region, the temperature is heading towards record highs. Expect the temperature to climb into the low 90's by noon time, and then touching 100 degrees in the midafternoon.
A Code Orange alert has been issued for the area, indicating unhealthy air conditions that can be harmful to those with respiratory problems. The National Weather Service has a heat advisory for the DMV area from noon until 8 p.m. Tuesday.
News4's Tom Keirein says that after the afternoon's torrid heat and humidity, expect a hot and muggy evening to follow. A chance of scattered thunderstorms is possible around 7 p.m.
The record high temperature for July 12 was set in 1908, when the region's thermometers went to 99 degrees. The hottest day ever in Washington was set on July 20, 1930, when temperatures went to 106 degrees.
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