Ashburn, Virginia

Extraordinary caution advised. Very high danger of dehydration, heat stroke, heat exhaustion and heat cramps.

Stay indoors in air conditioning or a well-ventilated area away from direct sun exposure.

Outdoor activity is dangerous and potentially life-threatening.

Loose fitting, light colored cotton clothing is recommended.

Extreme caution advised. High danger of dehydration, heat stroke, heat exhaustion and heat cramps.

Stay indoors in air conditioning or a well-ventilated area away from direct sun exposure.

Most outdoor activity is dangerous and potentially life-threatening.

Loose fitting, light colored cotton clothing is recommended.

Significant caution advised. Danger of dehydration, heat stroke, heat exhaustion and heat cramps.

Stay indoors in air conditioning or a well-ventilated area away from direct sun exposure.

Most outdoor activity is dangerous, especially for older adults, infants, and those with sensitive medical conditions.

Loose fitting, light colored cotton clothing is recommended.

Caution advised. Danger of dehydration, heat stroke, heat exhaustion and heat cramps if outside for extended periods, and especially while doing strenuous activities.

Stay indoors in air conditioning or a well-ventilated area away from direct sun exposure.

Minimize outdoor activity, especially for older adults, infants, and those with sensitive medical conditions.

Loose fitting, light colored cotton clothing is recommended.

Caution advised. Danger of dehydration, heat stroke, heat exhaustion and heat cramps if outside for extended periods, and especially while doing strenuous activities.

Older adults, infants, and those with sensitive medical conditions, should minimize outdoor activity and stay indoors in air conditioning or a well-ventilated area away from direct sun exposure.

Loose fitting, light colored cotton clothing is recommended.

Caution advised. Possible danger of dehydration, heat stroke, heat exhaustion and heat cramps if outside for extended periods, and especially while doing strenuous activities.

Older adults, infants, and those with sensitive medical conditions, should minimize outdoor activity and stay indoors in air conditioning or a well-ventilated area away from direct sun exposure.

Loose fitting, light colored cotton clothing is recommended.

Older adults, infants, and those with sensitive medical conditions should minimize outdoor activity, especially in the sunshine.

Loose fitting, light colored cotton clothing is recommended.

Most consider this temperature range ideal.

Light jacket or sweater may be appropriate.

Jacket or sweater is recommended.

Coats and hats are appropriate, consider gloves and a scarf.

Caution advised. Older adults, infants, and those with sensitive medical conditions, should be well dressed to protect from hypothermia and frostbite. Coat, hat, gloves and a scarf are appropriate.

Caution advised. Frostbite to exposed skin within 15 minutes. Hypothermia likely without protective clothing.

Limited outdoor activity recommended. Wear winter clothing that covers as much of the body as possible.

Caution advised. Frostbite to exposed skin within 8 minutes. Hypothermia likely without protective clothing.

Outdoor activity can be dangerous and should be limited. Wear thick winter clothing that covers as much of the body as possible.

Significant caution advised. Frostbite to exposed skin within 2 minutes. Hypothermia likely without protective clothing.

Outdoor activity can be dangerous and should be limited. Wear thick winter clothing that covers nearly all exposed skin.

Great caution advised. Frostbite to exposed skin within 1 minute. Hypothermia likely without protective clothing.

Outdoor activity is very dangerous and potentially life threatening. Stay in a heated area or, if outdoor activity is necessary, it should be limited to a few minutes and only if all skin surfaces are covered.

Extreme caution advised. Frostbite to exposed skin within 30 seconds. Hypothermia likely without protective clothing.

Outdoor activity is extremely dangerous and life threatening. Stay in a heated area or, if outdoor activity is necessary, it should be limited to a few minutes and only if all skin surfaces are covered.

Extraordinary caution advised. Frostbite to exposed skin within 20 seconds. Hypothermia likely without protective clothing.

Outdoor activity is extraordinarily dangerous and life threatening. Stay in a heated area.