Minnesota WeatherTalk

April continues trend of warm and wet:
So far this month most Minnesota climate observers are reporting warmer and wetter than normal conditions. Temperatures are averaging 5 to 7 degrees F warmer than normal. Through April 19th eight daily record maximum temperatures have been tied or set within the climate observation networks, while thirty-nine daily record warm minimum temperature records have been tied or set.

Precipitation this month has been in surplus across much of central and southern Minnesota, but deficit in west-central and northwestern counties. Thunderstorms have brought new daily precipitation records to nine climate stations so far, including 2.45 inches to Winona Dam on April 19th. A number of areas have reported measurable precipitation on over half of the days of the month and a total of over 3 inches. Some other observers in southeastern Minnesota report over 5 inches for the month. The abundant precipitation this month has prohibited farm field work in many…

April Snow and a Temperature Rebound:
Thunder and showers later on Sunday gave way to cooler temperatures and snow on Monday across portions of Minnesota. At times Monday night (April 10) into early Tuesday morning, snow showers were heavy for brief periods of time. Total snow accumulation across portions of central and southern Minnesota ranged from 1 to 3 inches in many spots. Observers in North Branch (Chisago County) and New Hope (northern Hennepin County) reported over 5 inches. Following the snow, the coldest temperatures of the month so far were reported, Many northern observers reported morning lows in the teens, while Embarrass and Seagull Lake went down to 12F. However a quick warm-up followed and the heavy, wet snow melted rapidly with temperatures climbing into the 50s and 60s F.

Over the first 9 days of April, the temperature pattern was consistently warmer than normal, with reports of four new record maximum temperatures set, including 81 degrees at Marshall on …

Dissecting climate trends in Minnesota month by month:
Several people have asked me in recent years if our Minnesota climate is changing more in certain months of the year than others. This is difficult depending on which climate attribute you are looking at. On a statewide basis I have looked at monthly temperatures and monthly precipitation and their measured changes over the past 100 years. Taking each value I have looked at the net change in mean monthly temperature and mean monthly precipitation per decade over the past 100 years and compared this net change to the 100 year average. Here are some examples:

For temperature, the biggest change has occurred in January with the monthly mean value now (most recent decade) that is 3.7°F higher than it was a century ago. This is a 57 percent increase relative to the 100 year mean monthly value for January temperature of 6.5°F (from a statewide calculation). By most statistical criteria this is a significant change in mean monthl…