Meteorologists say above-average temperatures likely this summer
Jul. 3—A heat advisory in effect from 1 p.m. Wednesday to 7 p.m. Friday is an introduction to what meteorologists expect will be above average temperatures in July, August and September.
Meteorologist Jennifer Saari with the National Weather Service in Huntsville said average high temperatures for the area this month will be 90 degrees while average low temperatures will be around 70 degrees. Saari said Tuesday's high was already above average at 93 degrees.
"Looking at my baseline data, we stay at a normal average high of 90 degrees until mid-July then it turns to 91," Saari said. "Then we stay at a normal of 91 through the end of July. The normal lows usually hang around 70. That's what the month of July typically provides as far as weather."
Meteorologist Kris White said local climate records show summer temperatures steadily rising each decade, which he attributes to human-induced climate change over the past century through actions like deforestation.
"With our temperatures here, especially during the summer, there is certainly an upward trend since the early 2000s, and then actually going back to the 1970s," White said. "For summer temperatures, the 1970s was our cool period."
White said the average summer temperature for north Alabama in 1975 was 76 degrees while the average summer temperatures over the last five years have been around 80 degrees.
"It doesn't sound like a lot, but averaging over 4 degrees (hotter) in an entire summer, that's a fairly significant difference," White said. "In 2010, it was actually the hottest average summer temperature recorded at 83.5 at the Huntsville International Airport. In Decatur, it was 82 degrees, and was also their hottest."
White said the Weather Service projects a heat index of up to 110 degrees Wednesday afternoon through Friday evening, triggering the heat advisory.
Local dew point temperatures have increased over the last decade as well, according to White, leaving less time for temperatures to cool at night and creating high heat indexes the next day.
"If you have higher dew points over the summer, you don't cool down as much at night," White said. "So, a lot of our temperature increases here in the summer months over the last decade or so have actually been recorded as higher nighttime temperatures. This increase in dew point temperatures is partly the cause of that."
Alabama Department of Public Health District Medical Officer Dr. Wes Stubblefield said heat exhaustion and heat stroke becomes a risk with the high temperatures and encourages the public to be aware of the weather when outside.
"With heat exhaustion, typically people start to feel poorly and being associated with heat exposure, they may feel dizzy or tired and may get nauseous," Stubblefield said. "These are the early signs of heat exhaustion. The best thing to do with people like this is get them to a cool environment to provide rehydration and look for signs of worsening."
Stubblefield said the next stage after heat exhaustion is heat stroke, where the body loses its ability to regulate heat. He said to call emergency services immediately if this happens.
"At some point, you become so dehydrated that you get so hot that your body can't regulate it anymore," Stubblefield said. "Your skin will become hot and dry, your temperature can rise rapidly to as much as 105 or 107 degrees, and it's life threatening. People will typically lose consciousness or become disoriented."
— wesley.tomlinson@decaturdaily.com or 256-340-2442.
