2019 was Iowa’s 12th wettest year on record, with an average of 41.49 inches of rainfall across the state, according to the state Department of Natural Resources. Rainfall in May, September and October was especially high, while the summer months experienced below average rainfall.
The two-year 2018/2019 period was the wettest on record, with 19 more inches of precipitation than average. Stream flows were above normal all 2019 following heavy snow in the winter months. The rainy spring and fall seasons are indicative of projected climate change models for the region.
2019 temperatures in Iowa were cooler than average, however, by 1.2 degrees Fahrenheit. During the January “Polar Vortex,”one station in Emmet County recorded a -59 degree windchill. Summer was slightly cooler than average, though July and September were warm, andChristmas week broke record temperature highs.
High temperatures on Wednesday, December 25 2019 broke records across the state of Iowa and much of the Midwest.
Des Moines reached 60 degrees, breaking the 1936 record of 58 degrees. Cedar Rapids reached 58 degrees, breaking the previous record of 54, according to Weather Underground.
The Christmas day highs were preceded and followed by unseasonably warm weather as well.
Though a 60 degree December day is not unheard of (the Des Moines Registerreports that at least one December day in Iowa has reach 60 degrees 29% of years since 1878), average winter temperatures in the Midwest are undoubtedly rising.
A Union of Concerned Scientists report shares that average annual winter temperatures in the Midwest have risen about 4 degrees since 1980. Winter temperatures are forecast to continue rising, while snow and days below freezing will decrease.
Some areas of the United States entered October in summer-like heat while others faced frosty cold and intense rain.
Dry heat is scorching the south and eastern parts of of the country. More than a dozen cities — including Cleveland, New Orleans, Nashville and Indianapolis — broke high temperature records for the whole month of October. The Weather Channel forecasts that records may continue to break through Thursday.
Meanwhile, states like Montana, Idaho and Wyoming felt unseasonable cold, with temperatures in 38 degrees Fahrenheit in Boise, Idaho. These temperatures follow a frosty weekend in the region, with record-breaking cold and snowfall.
The Weather Channel attributes the temperature extremes to an especially dramatic curve in the polar jet stream — a fast-moving, high-altitude band of wind that impacts weather throughout the hemisphere. Right now, the jet stream dips abnormally southward in the Western U.S. and soars abnormally northward in the east for this time of year.
Storms and floods along the stream’s path (where, the hot/dry and cool/wet air masses meet) are threatening parts of Minnesota, Iowa, Nebraska, Kansas, Colorado and New Mexico.
Studies say climate change alters the jet stream, intensifying weather phenomena like the “polar vortex,” though it is difficult to determine whether greenhouse gasses are playing a role in this week’s weather patterns.
The LA Dodgers, who won the game 3 to 1, might have owed something to the heat. High heat has been proven to have an effect on the distance a ball travels across the field. The University of Nevada-Reno’s Department of Math & Science put together a chart spanning analyzing the average number of home runs per game and the average distance of a batted ball, taking the temperatures of each game into account. After sifting through data from World Series games played between 2000-2011, they found that when the heat of a game spiked beyond 75 (the determined average temperature for an MLB game), home runs for any given team increased by an average of 2, while batted ball distance increased by roughly 2ft, suggesting that heat has a tangible effect on offensive play.
The first of its kind, a recent study found that climate change is likely to decrease the number of “nice weather” days worldwide.
The authors of the study, scientists from the National Oceanic and Atmospheric Association and Princeton University, define “nice” or “mild” days as those days when temperatures are between 64 and 86 degrees Fahrenheit, dew points are below 68 degrees Fahrenheit and less than half of an inch of rain falls. Currently there are an average of 74 nice days globally per year, but that number is likely to drop to 70 in the next twenty years and to 64 by 2081.
Karin van der Wiel is a postdoctoral researcher at Princeton University and lead author of the study. She said,
“We used a climate model to simulate the current climate. In that simulation we counted the number of mild days. Then, we increased greenhouse gases in the climate model to simulate the future effects of climate change. This leads to increasing temperatures, changes in humidity, changes in precipitation over the whole world and with very specific patterns. In this new, future climate, we counted the number of mild days again. We could then calculate the change — increase or decrease — of mild weather days for each location globally.”
Not all corners of the Earth will be affected equally, however. Tropical regions are expected to lose the most nice days, with some areas losing up to 50 per year by the end of this century. Meanwhile, London is expected to gain 24 nice days each year.
Predictions for Cedar Rapids, Iowa mirror global averages. Eastern Iowa currently enjoys 76 nice days annually; researchers say that number is expected to drop to an average of 72 between 2016 and 2035 and to 66 each year between 2081 through 2100.
Frequent high humidity makes it tough for Iowa to meet the pleasant weather criteria outlined in the study. Absolute humidity has risen by 13 percent during the summer months in Des Moines since 1970, according to Iowa State climate scientist Gene Takle. Increased humidity also contributes to the extreme rain events that have plagued Iowa in recent years.
van der Wiel said, “Mild weather is something everyone knows, experiences, and has memories of,” she continued, “Our study shows that human-caused climate change is going to lead to changes in mild weather all over… The changes are happening now, and where people live.”
Yet another record was set on Wednesday when the National Oceanic and Atmospheric Association (NOAA) released its annual Climate Report.
The report announced that 2016 was the hottest year on record for the third consecutive year. Deke Arndt is the chief of the monitoring group at NOAA’s National Centers for Environmental Information in Asheville, N.C.
Arndt said, “[Last year] was the warmest year on record, beating 2015 by a few hundredths of a degree, and together those two years really blow away the rest of our record.” He continued, “And that doesn’t sound like a lot, but when you take that and you average it all the way around the planet, that’s a big number.”
Rising temperatures were not limited to certain regions. Experts said that some part of every major ocean and every major continent experienced record heat. The Arctic, however, saw some of the most extreme warming. During Fall of 2016, temperatures were a full 20 to 30 degrees Fahrenheit warmer than average across large parts of the Arctic ocean.
Arndt said, “The long-term warming is driven almost entirely by greenhouse gases. We’ve seen a warming trend related to greenhouse gases for four, five, six decades now.”
The Climate Report, along with a separate analysis by NASA which duplicated its results, were released on the same day that confirmation hearings began for Oklahoma Attorney General Scott Pruitt, who has been nominated by President-elect Trump to lead the Environmental Protection Agency. Pruitt, who staunchly supports the fossil fuel industry, is identified as “a leading advocate against the EPA’s activist agenda” in his official biography.
The complete report and a summary of its findings can be found here.