Red Hot September Also Showed Wide Variation in Precipitation

BY DANIEL GRANT, FARMWEEKNOW.COM 

Many farmers hoped for some additional heat units in September to help late-planted crops catch up on maturity.

And most got just that.

The statewide temperature last month averaged a steamy 71.3 degrees, nearly 5 degrees warmer than the long-term average.

“If the preliminary numbers hold, it would be tied for the fourth-warmest September in Illinois since 1895 and actually the warmest since 1933,” said Trent Ford, state climatologist with the Illinois State Water Survey.

“We saw several (weather) stations, especially in the southwest and southern part of the state, break maximum and minimum daily temperature records.”

Farmers, however, ended the month with a very small portion of their crops in the bin due to lingering crop immaturity along with heavy rains in the north.

Just 4% of corn and 1% of the soybean crops were harvested across the state as of Sept. 30, which was 26 and 21 points behind the average pace, respectively.

The portion of the corn crop rated mature reached just 40% as of Sept. 30, 46 points behind average, while 77% of soybeans were turning color, 15 points behind the average pace.

“A few more machines move every day as we are getting tired of waiting for the harvest season to ramp up,” said Jeff Guilander, a FarmWeek CropWatcher form Jersey County.

More heavy rains in the northern half of the state last week, including some severe weather, certainly didn’t help the cause. Two tornadoes caused minor damage in central Illinois with one touchdown Sept. 27 in northeast Fulton County and the other Sept. 29 in northern Logan County, the National Weather Service reported.

Rainfall totals last month ranged from an astonishing 12 to 16 inches in northwest Illinois, which was 300 to 400% of normal at some locations including Jo Daviess County, to just .02 of an inch observed at weather stations in Pope and Massac counties in the southeast corner of the state.

“As far as precipitation, it was a contrasting story,” Ford said. “The September statewide average was 5.34 inches, about 2 inches above normal. But it really doesn’t tell the whole story.”

What caused such a stark contrast in rainfall totals in northern Illinois compared to the south?

“The majority of the state was under the influence of a high-pressure system, centered to the southeast,” which brought warm, dry air to the state, especially in the south, Ford noted. “The northern edge of the system (located in the northern half of Illinois) was predominantly the storm track for the month of September. It dropped quite a bit of rain.”

Looking ahead, cooler temperatures ushered in by a cold front late last week don’t appear to provide a major freeze threat any time soon. Forecast models show a low probability of minimum temperatures dipping to the 30s or close to freezing the first two weeks of the month.