May 08 | Climate Review and Weather Update
by Trent Ford, State Climatologist
ISWS PRI University of Illinois
Average temperatures in this first full week of May were actually a little cool, ranging from the high 40s in northern Illinois to the mid-50s in southern Illinois, between 3 and 8 degrees below normal. This followed an April that was a top five warmest on record statewide and felt like a bit of a bait and switch after a taste of summer-like weather last month. Nighttime temperatures regularly dipped into the 30s, and dropped below freezing in parts of northern and central Illinois, including 27 degrees in Rockford and 32 in Charleston.
We had a bit of a quieter weather week, though, with 7-day precipitation totals ranging from less than a tenth of an inch in northwest Illinois to just over 2.5 inches in east-central Illinois. The heavier rain along and just north of the I-70 corridor continued a wetter streak that has kept soils quite wet. Standing water can be seen in many fields from Champaign to Effingham, while soil temperatures have regressed a bit into the 50s and 60s due to the recent cool down.
Despite the wetter topsoils, very strong winds created dangerous blowing dust conditions in parts of central Illinois earlier this week. The National Weather Service issued dust storm warnings for a fourth consecutive year as recently worked soils were picked up by strong winds ahead of thunderstorms.
Looking ahead, temperatures will bounce around the 60s and 70s next week, ahead of what looks like a potential warm up in mid-May. The week 2 outlooks from the Climate Prediction Center show increasing chances of above average temperatures for the third full week of May, and outlooks hang on to that warmer trend through the last week of the month, too. Forecasted precipitation totals are mostly less than a half an inch for this next week, with no strong signals of drier or wetter patterns for the latter half of May. So, even though the first part of the month hasn’t been ideal for planting or strong emergence in many places, there may be better fieldwork weather on the horizon.