As summer 2024 nears, excessive heat to smother Delaware, much of East Coast this week
With the Summer Solstice right around the corner, scorching heat has arrived just on time.
The National Weather Service in Mount Holly, New Jersey, is predicting that several high temperature records will be broken this week as an increasingly hot air overspreads across the region.
What is the weather in Delaware?
Much of Delaware will be under a heat advisory from 10 a.m. Tuesday to 6 a.m. Wednesday before entering an excessive heat watch Wednesday morning through Saturday night, according to the National Weather Service.
The hottest temperatures will hit Friday and Saturday and could potentially last into next week, the NWS said.
The NWS is projecting daily and monthly high temperature records with maximum heat indexes reaching as high as 105 degrees in parts of the Northeast. Overnight temperatures will only drop into the mid 70s, providing little relief.
Most of Delaware will be at a major heat risk, with a high of 90 degrees Monday before the temperature reaches as high as 99 degrees Friday in Wilmington.
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What is the difference between a heat advisory and a heat warning?
Here's the breakdown from the National Weather Service:
Excessive Heat Warning: An excessive heat warning is issued within 12 hours of the onset of extremely dangerous heat conditions. The general rule of thumb for this warning is when the maximum heat index temperature is expected to be 105 degrees or higher for at least two days and night time air temperatures will not drop below 75 degrees. These criteria vary across the country, especially for areas not used to extreme heat conditions. If you don't take precautions immediately when conditions are extreme, you may become seriously ill or even die.
Excessive Heat Watches: Heat watches are issued when conditions are favorable for an excessive heat event in the next 24 to 72 hours. A Watch is used when the risk of a heat wave has increased but its occurrence and timing is still uncertain.
Heat Advisory: A heat advisory is issued within 12 hours of the onset of extremely dangerous heat conditions. This advisory is when the maximum heat index temperature is expected to be 100 degrees or higher for at least two days and night time air temperatures will not drop below 75 degrees. These also vary across the country. Take precautions to avoid heat illness. If you don't take precautions, you may become seriously ill or even die.
Excessive Heat Outlooks: The outlooks are issued when the potential exists for an excessive heat event in the next three to seven days. An outlook provides information to those who need considerable lead-time to prepare for the event.
What is the heat index?
The heat index is what "the temperature feels like to the human body when relative humidity is combined with the air temperature," according to the National Weather Service. The combined reading of temperature and humidity is a better estimate of how the human body is feeling the heat.
"When the body gets too hot, it begins to perspire or sweat to cool itself off. If the perspiration is not able to evaporate, the body cannot regulate its temperature. Evaporation is a cooling process ... When the atmospheric moisture content (i.e. relative humidity) is high, the rate of evaporation from the body decreases. In other words, the human body feels warmer in humid conditions," according to the weather service.
Record high temperatures
Here are the record high temperatures in Wilmington that could be broken this week:
June 18: 95 degrees in 1957
June 19: 100 degrees in 1994
June 20: 97 degrees in 2012
June 21: 98 degrees in 2012
June 22: 98 degrees in 1988
This article originally appeared on Delaware News Journal: What is the weather? Excessive heat to hit Delaware this week
