March’s warmer than average temperatures are expected to continue into April, which could lead off a warm and wet spring all the way into June, according to Illinois State Climatologist Trent Ford at the University of Illinois’ Illinois State Water Survey.

Mild temperatures from February carried over to the first half of March in Illinois. Most of the first 15 days of March were warmer than normal in the state. A strong storm system pulled in very warm and humid air from the Gulf of Mexico on March 5, sending high temperatures into the 70s and 80s across the state. However, the second half of the month had more days with below normal temperatures and multiple rounds of sub-freezing nighttime low temperatures.

The preliminary statewide average March temperature was 45.8 degrees, 4.4 degrees above the 1991–2020 average and the 14th warmest on record going back to 1895. March average temperatures ranged from the low 40s in northern Illinois to the low 50s in southern Illinois, between 2 and 5 degrees above normal. The warmest place in the state last month was Du Quoin at 53.4 degrees on average, and the coldest place in the state last month was Stockton at 39.6 degrees.

The first two months of the year included a wet January and dry February, but March divided Illinois with wetter conditions in the north and drier conditions in the south. March total precipitation ranged from over 6 inches in north-central Illinois to less than 2 inches in southern Illinois. Most of the state north of Interstate 70 had a near-normal to wetter than normal March, while much of southern Illinois was 1 to 3 inches drier than normal

Overall, the preliminary statewide average total March precipitation was 3.09 inches, 0.15 inches above the 1991–2020 average.

While March wasn’t nearly as active for severe weather as last year, some of Illinois’ precipitation was hail. The Storm Prediction Center’s preliminary count had 68 severe hail reports across Illinois last month, including eight reports of 2-inch or larger diameter hail.

March also brought some snowfall to northern Illinois, but ended with below-normal snowfall statewide, adding to deficits from the rest of the snow season. Most places north of Interstate 80 saw some accumulation in March, with some isolated 8- to 9-inch totals in Boone and McHenry Counties.

Outlooks

April is an important weather month in Illinois because it ushers in a typically wet three-month period that also brings the highest threat of severe weather. April is also when spring fieldwork and planting begins in earnest across the state.

The final April outlook from the Climate Prediction Center has highest chances of warmer and wetter than normal conditions in this important month. The April–June period also leans warmer and wetter than normal in Illinois.

For more information about monthly Illinois weather summaries, current conditions, and climate, visit the Illinois State Climatologist website.