In the upper Mississippi River Delta region, cotton usually is planted during the first two weeks of May. For good germination, seeds require warm soil conditions. A midmorning soil temperature of 65 degrees Fahrenheit is a good threshold temperature for planting cotton. Historically, weather trends show that planting after May 15 reduces the risk of low soil temperatures, though an early frost in October can significantly reduce yields in late-planted cotton.
University of Missouri Extension takes out some of the guesswork for farmers with its statewide network of electronic weather stations, which provides soil temperature information.
Most of them operate in “real time,” meaning that they update every five minutes. Farmers can monitor soil temperature from a nearby station by bookmarking the station’s website on their cellphone.
To find a station near you, go to the Missouri Mesonet site at http://agebb.missouri.edu/weather/stations/ and select a location under the “Real-Time Conditions” header (second option). An alternative way to check soil temperature is to select “2” Soil Temperatures for Missouri” (fifth option) on the Missouri Mesonet site and view the table showing low and high bare soil temperatures around the state in the last 24 hours.