COLUMBUS (WCMH) — July has been a scorcher in central Ohio.
The average temperature in Columbus of 79.95 degrees (5 degrees above normal) presently ranks as the fourth warmest month in the city since 1879. The average high temperature of 91.45 degrees is less than 0.1 degree shy of the July 1936 record for daily-maximum readings (through July 20).
The July heat records currently being challenged in central Ohio date back to the drought summers in 2012 and 1999, but the extreme temperatures this month fall well short of the infamous Dust Bowl era of the 1930s, when the midsection of the country was devastated by a prolonged drought. Great dust blizzards comprising windswept parched soil reached the East Coast in 1935.
The high temperature in Columbus in July 1934 and 1936 peaked at 106 degrees. An all-time state record of 113 degrees was recorded at a weather station in Gallipolis on July 21, 1934.
Two summers later, during a blistering week from July 8-15, 1936, the temperature topped 100 degrees in Columbus each day. The highest reading in the state was 111 at Paulding on July 10 in the northwest part. Crops withered in the field and highways buckled in the extreme heat.
So far this summer, the mercury has reached 90 or higher on 23 days in the city. During an earlier heat wave that commenced on June 29 and continued for 12 days, four air quality advisories were issued for the Columbus area (Franklin, Delaware, Licking, and Fairfield counties).
The issuance of an Air Quality Alert Day by the Mid-Ohio Planning Commission (MORPC) is based on a projected value of the Air Quality Index (AQI) above 100, which is considered unhealthy for sensitive populations, particularly young children, the elderly, and people who have respiratory (COPD, asthma) or cardiovascular disease. Prolonged or heavy outdoor activity on hot days can worsen these conditions during peak heating times.
“Ozone formation is driven by sunlight, and higher temperatures make those reactions go more quickly so that we build up more ozone in our region,” said Brooke White, air quality specialist with MORPC. White said high-moderate levels of ozone were expected to persist until a general rainfall and better mixing occur, though staying below the threshold for an alert day.
Nitrogen oxides and volatile organic compounds (VOCs) created by combustion react with sunlight on hot, sunny days to produce ground-level ozone, which irritates our lung tissue. The primary sources of these compounds released into the air are motor vehicles (transportation), coal-fired power plants, and factories. VOCs are also produced by natural sources such as trees and vegetation.
Fortunately, during the current 90-degree stint that began last Thursday, no air quality alerts were issued for the Columbus region due to breezy weather. The Dayton and Cincinnati metropolitan areas were under air quality alerts because of hotter, stagnant conditions.
The dry weather the past six weeks is also causing lawns to turn brown and stressing crops, especially in the northwestern part of Ohio. “In the summertime, we get a lot of really intense evaporation. We lose a lot of water from the surface really efficiently,” said Aaron Wilson, a climate scientist with OSU Extension and the Byrd Polar & Climate Research Center.
“Localized thunderstorms really aren’t enough to keep up with the water balance this time of year,” when the afternoon sun is highest in the sky compared to the rest of the year, Wilson added.
The heat has been extremely uncomfortable across a large swath of the nation. The heat index peaked at 114 degrees (factoring in the humidity) at Edenton, N.C., and Plant City, Fla., on Sunday. The peak heat index in Columbus reached 100 degrees at 2 p.m. Sunday.
Evaporation of moisture from your skin is limited when the heat index reaches 100, which makes it difficult for perspiration to cool the body properly. The persistent, intense heat adds to the heat stress outdoors and increases the risk of heatstroke with prolonged exposure and inadequate fluid intake.