Why is it so hot in Kansas City? And where does the fog come from? Here’s what we know
Temperatures are soaring in Kansas City this week, with extreme humidity bumping up the heat index and glazing windows around the metro with steamy condensation.
For the fourth consecutive day, Kansas City was forecast to see its temperatures rise into the mid- to upper 90s while high dew points were expected to make it feel more like 110 to 120 degrees, according to the National Weather Service.
This hasn’t been regular hot summer weather in Kansas City. By some measures, it’s never been hotter.
“These are some of the highest values that a few of the reporting stations in the Kansas City metro have reported in recorded history,” said Alex Krull, a meteorologist at the weather service’s Kansas City office.
But where does this extreme weather come from? And what do we know about its potential impacts?
Here’s the latest on the recent heat wave and what it means for Kansas City residents.
Why has it been so hot and humid?
Most of the hot, muggy air in the Kansas City region comes from the Gulf of Mexico, Krull said.
He added that the large high pressure system blanketing the country is centered on Kansas City.
And our dew point, a metric which measures the amount of water in the air, is especially high.
“If you look at other locations through the upper Midwest, they have similar air temperatures to us, but their dew point and their overall humidity is lower,” Krull said. “Therefore, they’re not necessarily seeing those elevated heat index values that we’ve been experiencing here.”
The heat index is a combination of heat and humidity presented as the “feels like” temperature on your weather app.
On Tuesday afternoon, it was around 103°F at Kansas City’s downtown airport. It reached its highest point in recent weeks on Sunday around 4 pm, at 121°F.
Where does the fog come from?
You may have woken up to steamy windows or noticed fog hanging over downtown Kansas City in the morning. This is caused by the air temperature lowering just enough overnight to meet the high dew point in the area, Krull said.
“When the dew point temperature has been around 81°, and the overnight temperature drops to 81°, that means that the temperature has reached the point where the air can saturate (with water) and form a cloud,” he explained.
“The technical definition for the dew point temperature is the temperature at which water vapor in the air would become liquid water.”
This liquid water is the droplets on the outside of your windows, the fog clouding your glasses and the haze visible in the morning.
What does the current high heat and humidity mean for Kansas City?
Krull laid out a few ways the current high temperatures may impact your daily life.
Poor air quality: Clear sunny skies and low wind are the perfect combination needed to create ground-level ozone, also known as smog. The National Weather Service issued an air quality alert for Tuesday’s ozone levels, and is advising residents to limit strenuous outdoor activities.
Power grid strain: With heat index temperatures in the triple digits, most residents will be running air conditioners to cool down, Krull said. This can increase the strain on the power grid, potentially leading to blackouts. You can report an outage to Evergy online or by calling 888-544-4852.
Pavement buckling: With temperatures this hot, asphalt on roads and highways can warp, Krull said. Drivers might notice some extra bumps or wider gaps in the pavement. Last month, a KC Streetcar track buckled due to the heat, shutting down the system for 17 days.
When can Kansas City expect relief from high temperatures and humidity?
Overheated Kansas Citians will be happy to hear that meteorologists expect a cool front to move through the metro on Friday, lowering temperatures back into the 80’s over the weekend.
While air temperatures are expected to rise again next week, Krull said that the dew point will likely stay low, hopefully keeping the heat index in the double digits.
But don’t get too comfortable — experts believe that record-breaking heat will become more frequent as a result of global climate change. One study projects that the Kansas City area will experience at least one day per year with a heat index above 125°F within the next 30 years.
“There’s definitely evidence out there to see a change in temperature trends across most of the United States and really across most of the globe,” Krull told The Star.
The Star’s Robert A. Cronkleton contributed.
Do you have more questions about the causes of extreme weather in Kansas City? Ask the Service Journalism team at kcq@kcstar.com.