Curious Iowa: When did Iowa have record-setting weather?

July 2023 was the hottest month ever recorded in human history. Records across the world were shattered.

Records are hard to break and one curious Iowan wondered what some of Iowa’s state weather records have been. Curious Iowa is a series from The Gazette that seeks to answer Iowans’ questions about the state, its culture and the people who live here. We looked at the hottest and coldest days in Iowa’s history and the day with the most snowfall. We also talked with state climatologist Justin Glisan about weather dynamics and how patterns are changing.

Since 1895, Earth’s average surface temperature has increased about 1/10 of a degree per decade.

Glisan said today the earth is about 1.3 degrees warmer than it was at the end of the 19th century. When atmospheric temperature rises, it increases the amount of water vapor held in the atmosphere.

“When we have more water vapor in the atmosphere, in a warmer atmosphere, it takes more water vapor loading to produce a meteorological event,” Glisan said. “And hence, we’re seeing a shift form gentle less-than-an-inch rainfalls over 24 hours to these more intense and frequent downpours or thunderstorms that produce two, three-inch, four-inch totals over 24 hours.”

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Glisan said the rising temperature is a product of the greenhouse effect, which describes the buildup of solar radiation in a planet’s atmosphere.

“The [Arctic ice cap] floats on the Arctic Basin and it acts to reflect incoming solar radiation so it kind of acts as an air conditioner for the mid-latitudes or the northern hemisphere,” Glisan said. “We’re losing that ice cap. It’s melting from the bottom up and the top down because of warmer ocean temperatures depleting that sea ice.”

As the ice caps melt, the amount of solar radiation that is reflected out decreases.

The extreme records for hottest day, coldest day and most snowfall in Iowa haven’t been tied or broken in the 21st century, but other records have. The wettest two calendar years on record were 2018 and 2019. In Iowa, 2018 was the second wettest year on record.

And new weather events have been recorded. On Dec. 15, 2021, Iowa experienced its first derecho in the month of December along with an outbreak of 63 tornadoes. That day broke the 1950 record for most tornadoes in Iowa and the most EF-2 or stronger tornadoes in a single day.

The high temperature that day was reported as 75 degrees across several stations in southern Iowa. That broke the previous record of 74 degrees from back in the 1900s, Glisan said.

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Iowa’s coldest day destroyed carloads of oranges

On Jan. 12, 1912, the temperature reached minus 47 in Washta, Iowa. The cold temperature began earlier that month. On Jan. 1, The Evening Gazette’s front page read “All Iowa Records for Cold Broken.”

The cold was especially difficult for the railroads, which were hit hard with financial loss because trains were running behind schedule. The Gazette reported that a carload of oranges was lost after “heroic efforts” to prevent them from freezing. “Two heaters were placed in the car, but … succeeded only in keeping the temperatures from descending lower than 14 below zero.”

On Feb. 3, 1996, Elkader tied the cold temperature record. The Gazette reported that it was the fifth straight day the temperature would stay below zero in Eastern Iowa.

Over in Clinton the KLNT/KCLN radio station’s main sewer pipe froze and broke earlier in the week. Unfortunately, the portable toilet was too large to make it into the station and remained outside. Employee Sue Christiansen told The Quad-City Times that there was a small, ceramic heater in the outhouse that was ineffective and toilet paper was kept inside where it was warm.

Despite the freezing temperatures around the state, The Des Moines Register reported that some presidential hopefuls made their campaign stops as planned.

Iowa’s hottest days ‘turned city pavement to bake ovens’

On July 20, 1934, the temperature reached 118 in Keokuk. That day the Ames Daily Tribune described southern Iowa as a “victim of drouth, chinch bugs and oppressive heat” that “for months received the brunt of the punishment by a relentless sun that turned city pavement to bake ovens.”

Three drownings were reported as Iowans tried to escape the heat.

Iowa’s record snowfall dropped two feet

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On April 20, 1918, 24 inches of snow was recorded in Lenox, Iowa. It’s hard to imagine what that much snow looks like and there aren’t Gazette photos from that storm. But 50 years ago, in April 1973, a blizzard dropped 15 to 19 inches of snow on Eastern Iowa. Photos from The Gazette archives show abandoned cars and thick snow drifts.

Who decides when a weather record has been set?

Today, if an extreme weather event ties or breaks a record, the State Climate Extremes Committee is brought together to verify the data. That committee was established in 2006 and is made up of the state climatologist, meteorologists and other physical scientists.

Iowa — and other parts of the Midwest — are experiencing a drought that has stretched over multiple years. Glisan explained that lack of rainfall stacks up and exceptional drought can occur even in the winter.

“The ground is frozen, so even if you’re getting snowfall events, you’re not infiltrating any of that water into the ground.” Glisan said.

There have been pockets of drought recovery. Those include October 2021, which was the state’s eighth wettest October, and December 2022, which helped replenish soil profiles before they froze.

Glisan explained that if there is moisture in the profiles, they don’t freeze as deep or as fast.

“As we get into a spring melt, we’re able to infiltrate snow pack that is melting, so you’re able to start to chip away at those precipitation deficits,” Glisan said. “But if you have 170 weeks in which you have precipitation deficits somewhere in the state and you get into the heat waves that we had after the state fair or you persist with dry conditions … that’s where you’re able to perpetuate those drought conditions even through seasons when you wouldn’t expect that.”

Where is weather data recorded?

The state of Iowa has more than 160 National Weather Service co-op stations. These are where observers report the weather at 7 a.m., which is when a new meteorological day starts. Not every co-op station reports daily.

“Some don’t report on the weekends,” Glisan said. “For example, some are located at water treatment plants or some are located at police stations so they’re not always staffed.”

Glisan said some co-op stations have been in families for decades and are run by longtime observers. Airports are another source of weather data as they monitor weather hourly.

Iowa’s first National Weather Service co-op station was in Muscatine.

“I have the actual paper weather observations from Muscatine that go back into the 1800s and some of these weather observations are 100 years old,” Glisan said.

The stations have standardized ways of measuring weather data. For example, temperatures are taken in the shade to ensure accuracy.

“Snow is a very important meteorological observation and it’s one of our most difficult to take,” Glisan said.

Observers use a ruler and measure in at least three different locations. Then, they average the measurements together. Averaging helps eliminate anomalies caused by snow drifts. Other tools, like heated rain gauges can melt snow for a liquid equivalent measurement.

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Comments: bailey.cichon@thegazette.com