Eastern Iowa Among the Most Extreme Climates in the World?

Alert, Nunavat, Canada

The arctic circle is home to some of the the coldest air on the planet, second only to its polar opposite, the antarctic circle. At the heart of the arctic ocean is the north pole at 90°N latitude. Here the sun does not rise for half of the year. Roughly 500 miles away, Alert, Nunavut, Canada is the northernmost inhabited community on earth at 82°N latitude. Here the record low is -58° in February and the record high is 68° in July. The average low in February is -34.5° and the average high in July is 43°.



In a hypothetical situation, a 10 mph breeze and a temperature at the average February low of -34.5°, the wind chill would be around -60°.

Manaus, Brazil

On the other hand, the equator, 0° latitude, is home to some of the warmest and most humid weather conditions on the planet. The sun stays in the sky about 12 hours a day year round. About 3° south of the equator, Manaus, Brazil is nestled into the middle of the Amazon Rainforest.  There, an average high temperature is between 86 and 90 degrees all year long with dew points seldomly dropping below 70 degrees.



In a plausible situation, a temperature of 90 with a dew point of 85 would yield a heat index of about 117 degrees.

Both of these places are so difficult to live in because of their location on the globe which affects how much solar radiation they take in, earth’s primary heating source. In Alert, there is a wide annual swing in temperatures but due to their northern extent, temperatures range from extremely cold to mild at best. In Manaus, there is almost no change year round: the climate is hot and steamy throughout the whole calendar.

Eastern Iowa

The KWWL viewing area lies roughly between latitude 41 to 43, pretty much in the middle of the two extreme locations listed above. Doesn’t that mean our climate should be snuggled in between the extreme cold and extreme oppressiveness – a goldilocks climate? For the most part, yes. The difference between our home and the locations listed above is that our seasons are way more cyclical. For a majority of the time, our climate is comfortable as we swing between july average highs in the middle 80’s and a January average low around 10°.  At worst we get a few hours per year of bone shattering wind chills and a few hours per year of face melting heat and humidity.

Check out this map produced by climatologist Brian Brettschneider showing the difference between the lowest wind chill and the highest heat index in 2019 for weather stations all across the U.S. and Canada. The bullseye is right over eastern Iowa with a difference of over 160° – talk about extreme.

Here is a close up of that same map:

This comes after our recent July heatwave where heat indices neared 115° subtracted from our lowest wind chill of about -60° in late January.

2019 Highest Heat Index Coldest Wind Chill Difference
Waterloo 113° -55° 168°
Dubuque 111° -55° 166°
Cedar Rapids 111° -55° 166°
Iowa City 116° -50° 166°

2019 values rounded, may differ from values in map above

Turns out 2019 has been fairly anomalous. From another graphic produced by Brian Brettschneider showing the climatology from 1998 to 2018 of the same parameters, a typical perceived temperature range for eastern Iowa spans from 130° to 150°. That is nothing to scoff at and is comparable to Minnesota, the Dakotas, parts of Canada, and even the arctic circle. Turns out Iowans are a pretty hardy people.

While we get to enjoy a yearly cycle taking us through four different seasons, the swings in temperatures – and apparent temperatures – place Iowa in one of the most diverse climates on the planet. In the dead of winter and the dog days of summer we get just a tiny taste of the climate in the arctic circle and tropics respectively. Most of the time, we enjoy some very comfortable and less extreme conditions. We live in a place that is definitely worth bragging about.

Brandon Libby

Brandon Libby

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