Des Moines experienced its first freeze (32° or colder) Monday morning, November 1st, as lows fell to 31°. This was the latest first freeze in five years, and also the first time in five years not seeing snow in the month of October.
On average Des Moines experiences its first freeze on or around October 18th, but due to a warmer upper level pattern, above average temperatures held on through the third week of October, before a couple different waves brought a much colder pattern into the state. Despite the late first freeze, there are 15 other years since 1893 which recorded a later first freeze. The latest first freeze for Des Moines occurred on November 13, 2015.
About half of sites that are measured across the central Iowa area have not only seen their first freeze, but also their first hard freeze. A hard freeze occurs when temperatures fall to or below 28° for at least a few hours. On average the first hard freeze for Des Moines is on or around October 28th. While nearly half the state has not experienced their first hard freeze, it is likely to occur this week. Forecast lows over the next couple mornings (Tuesday and Wednesday) are in the mid to upper 20s, and if the sky remains clear in most spots, a hard freeze is likely to occur.
How long will the 20s last?
Even though the first hard freeze for Des Moines will be a few days later than average, technically 20s are still below average for early November. Average lows don’t fall into the 20s until November 18th. So what’s ahead for the next couple weeks in Iowa? Well, by the end of the week lows will likely climb back into the 30s, but warmer weather is expected beyond the 7-day forecast.
According to the Climate Prediction Center’s 8 to 14 day outlook, temperatures are more likely to be above average than average or below average. The 8th day would be November 9th when the average high is 51° and the average low is 33°. The 14th day is November 15th when the average high is 49° and the average low is 30°.