DES MOINES, IOWA — The Des Moines metro area just its coldest four-day streak in the last 25 years … but the previous coldest streak in 1996 still holds this bragging rights.
From February 13th-16th this year, Des Moines saw an average temperature of -5.3 degrees. From January 31st to February 3rd, 1996 – the average temperature was -12.7 degrees.
Similar four day streaks of extreme cold also blanketed the state of Iowa in December 1983, December 1989 and in January 1994. However those cold streaks were all ‘warmer’ than what we just all went through in the last week.
If you extend the extreme cold window to ten days then 2021 does beat out 1996. The 10-day average high temperature earlier this month was -2 degrees. In 1996, the coldest 10-day stretch averaged -1.8 degrees. A ten-day stretch of December 1983 tops both of those. The average high during that stretch was -7.1 degrees.
Despite those frigid lows, the length of ‘cold snaps’ in Iowa has actually decreased in recent decades. Since 1970, the average ‘cold snap’ was 19 days. In 2019 it was just 11 days. That doesn’t mean that we aren’t seeing colder individual days, just that the length of the cold streaks has shortened over time.
The coldest temperature recorded in Des Moines each year actually continues to get rise. In 2020, the average low temperature was 6.4 degrees warmer than it was in 1970. Historically, Iowa set record high temperatures as often as it set record lows, but that is no longer the case. We are now twice as likely in Iowa to break a record high temperature than we are to setting a record low.