Hour-by-Hour to Feels Like 109 Degrees: Virginia Weather Forecast

Dangerous heat in the forecast across Northern Virginia will keep many people inside this weekend, with those going outside forced to take precautions to protect themselves, according to the National Weather Service.

Temperatures Saturday morning are expected to climb into the 90s by 10 a.m., with the heat index, or "feels like" temperature reaching 109 by mid-afternoon.

An excessive heat warning is in effect from 10 a.m. until 11 p.m. Saturday across the region. The heat index could climb to 115 degrees for some on Saturday, according to the weather service.

An excessive heat warning means that a prolonged period of dangerously high temperatures, with heat stroke and other heat-related illnesses expected, according to the weather service.

Here is the timeline for today's "feels like" temperature:

10 a.m.: 99 degrees

11 a.m.: 105 degrees

noon: 107 degrees

2 p.m.: 109 degrees

5 p.m.: 107 degrees

6 p.m.: 105 degrees

7 p.m.: 103 degrees

8 p.m.: 101 degrees

9 p.m.: 98 degrees

10 p.m.: 96 degrees

Heat tips include:

• Rescheduling strenuous activity to early morning or evening
• Knowing the signs and symptoms of heat exhaustion and heat stroke
• Wearing light and loose fitting clothing
• Drinking plenty of water

Those working outside should take frequent breaks in the shade or in an air-conditioned environment. "Heat stroke is an emergency - call 911," the weather service warns.

An excessive heat watch will be in effect from noon until 8 p.m. Sunday, according to the weather service, meaning heat-related illness will be likely. Temperatures are expected to hit 100 degrees, again, with a heat index at 109 degrees by mid-afternoon.