This year will be the warmest year on record in Missouri since 1895, when established instrumental temperature records began, according to Pat Guinan, extension climatologist with the University of Missouri Commercial Agriculture Program.
Guinan presented his findings at the MU Crop Management Conference, Dec. 18 in Columbia, and at the recent Missouri Livestock Symposium in Kirksville.
December temperatures were running well above normal, punctuating a year dominated by unusually high temperatures and drought. The year could also rank among the top 10 driest years on record, and driest since 1980, but we won't know for certain until all the data for the state are processed, Guinan said.
Since the spring of 2010, only a handful of months have had below-normal temperatures in Missouri, Guinan said. March 2012 had temperatures that were an incredible 14 degrees above normal, giving farmers a record head start on planting corn crops.
"Warm spring trends over the past few decades have extended the growing season," Guinan said. "Our median spring freeze date is occurring three to four days earlier compared to the long term."
The median date of first fall frosts has not changed much, he said.
Many sunny days in May and June, coupled with above-normal temperatures and below-normal relative humidity, led to unusually high moisture loss from soils, water surfaces and vegetation. The high evaporative losses, in combination with lack of rainfall, resulted in a "flash drought" across the state.
Reports of deteriorating pastures, declining soil moisture reserves, limited stock water supplies and crop stress increased significantly as summer progressed.
Drought impacts continued to mount in July, including widespread crop and pasture losses, livestock stress and declining stock water and hay supplies. Hydrological issues such as dry wells and streambeds, low river levels and rural and urban water restrictions were increasingly common.
Even with burn bans in place, grass fires and forest fires continued to be reported. The extreme conditions affected gardens, lawns, trees and shrubs, with numerous instances of vulnerable species succumbing to water and heat stress.
Wildlife was affected by the lack of healthy vegetation and dwindling water resources. By the end of July, Missouri had the distinction of having the worst corn, soybean and pasture conditions in the United States, according to the National Agricultural Statistics Service. It was also the third-warmest and driest May through July on record for Missouri.
The remnants of Hurricane Isaac brought the first widespread relief to the state at the end of August. Some stressed vegetation began to green up again, but for many crops and other plant species the damage had already been done.
Even though overall drought conditions improved across portions of Missouri this fall, a complete recharge of water resources above and below the ground had not been realized by the end of December.
Winter is typically the dry season in Missouri and it is unlikely that surface and ground water supplies will fully recover for the start of next year's growing season in many parts of the state.
The highest likelihood for hydrological drought carrying over into 2013 is across northwestern Missouri, which typically receives only three to four inches of precipitation between December and February -- not nearly enough to make up for a year-end precipitation deficit of more than a foot.
Southern and eastern sections of the state have better chances for drought recovery. Heavier autumn precipitation has occurred there and more winter precipitation generally falls.
For more climate information, go to climate.missouri.edu.