Chilly springs have been the recent trend; 2020 looks different
Recent spring seasons have trended "chilly" here in South Bend, but that doesn't look to be the case for 2020.
While spring 2020 is forecast to have above normal temperatures, since 1970, the season’s normal temperature has stayed relatively the same. Springs 2018 and 2019 both had temperatures below normal for the season. Spring 2017 was at the normal temperature for the season. Springs 2015 and 2016 had warmer average temperatures than the normal.
Across the nation, temperatures are trending warmer. This graphic from a Climate Central study shows temperature changes during the spring season (March, April, and May) from 1970-2019. Areas in a darker red, like the southwestern United States, have seen the greatest increase in spring temperatures. Areas in blue or white have seen a decrease in spring temperatures since 1970, or have not changed. There are only a few areas like this. Michiana is a light red, meaning our spring has warmed just over one degree in the last 50 years.
Specifically looking at South Bend, however, the average spring temperature has not changed much. It has stayed right around 49 degrees, indicated by the horizontal trend line. This is partly to do with our proximity to Lake Michigan-- we stay gray and cooler than other large cities in the midwest.
Compare our trend with Indianapolis. Just 130 miles to our south, the average spring temperature has warmed over two degrees in the last 50 years. That makes our constant 49 degrees seem more significant.
These graphics only include up to 2019, the last full spring season. Spring 2020 started off with a mixture of above and below normal temperature days in March. 19 days were above normal, with 10 below. Two days were at the normal temperature.
The average mean temperature for the month was 40.9 degrees. This is about 9 degrees below the spring normal, but with April and May-- two two warmer months-- to come, spring 2020 might end up being above normal temperature. If this happens, we will not follow the trend from the last 50 years.