COLUMBUS (WCMH) — A heat advisory is in effect this afternoon until 7 p.m. for central and southern Ohio, along and south of the Interstate 70 corridor to the Ohio River.
The return of the “heat dome” sent readings up to 95 degrees in Columbus Tuesday–hottest of the summer season so far. Record highs were observed at Cleveland (95) and Toledo (100).
At 2 p.m. Wednesday, the heat index reached 109 in Columbus, with a temperature of 96 degrees, closing in on the daily record of 97 set in 1888 and tied in 1988.
Soaring temperatures coupled with high humidity create dangerous conditions if a person is not sufficiently hydrated, which means drinking plenty water and taking advantage of the shade when spending time outdoors.
The NWS usually issues a heat advisory based on high temperatures and humidity generally exceeding 100 degrees. Based on NOAA’s heat index chart, a 90-degree day feels like 100 degrees at 60% relative humidity.
On a humid day, the body has more difficulty cooling efficiently, raising the risk of heat illness. The greatest impacts are felt by those with respiratory and heart conditions, children, and the elderly.
Spending time outside for a period of time requires that you pay attention for early sings of dehydration that can lead to heat exhaustion or heat stroke, such as feeling faint or light-headed, nausea, hot and reddening skin, and rapid breathing.
According to the Centers for Disease Control and Prevention, in an average year about 700 people in the United States die from heat-related causes, and more than 9,000 are hospitalized due to heat-related illness.
During periods of dangerous heat, never leave pets and children inside a vehicle. Interior temperatures can quickly rise 20-35 degrees higher than the outside temperature. Pavement temperatures often rise 35-40 degrees higher than air temperatures.
Drink plenty of water, take breaks if working outdoors, avoid strenuous activities, look for shady spots and air conditioning, and wear lightweight, light-colored clothing.
The heat this week will ease a little on Thursday, as highs fall back into the mid-80s following the passage of a weak cold front. However, low 90s are expected to return by the weekend.
An excessive heat warning was in effect for much of Ohio last Tuesday and Wednesday for the first time since July 18-20, 2020.
Last week, the combination of heat and humidity last week created an oppressive “feels like” heat index of record 117 degrees at 6:45 p.m. on June 14, eclipsing the previous Columbus record of 116 on July 15, 1995.
The National Weather Service in Wilmington noted that in previous years the dew point was generally measured hourly and not sampled as frequently, so it is possible there was a comparable heat index in an earlier heat wave.