With the calendar now turning to mid-May and much warmer weather expected ahead, this will be the last edition of this year’s soil temperature series in the C.O.R.N. Newsletter. Thanks especially to Elizabeth Hawkins and Sam Custer for persistently supplying daily soil temperatures records from their locations this spring.
Figure 1 shows that two- and four-inch soil temperatures cooled once again after spending the first part of May recovering from April’s chill. Air temperatures were 8-12°F below average for the week which sent soil temperatures in the wrong direction. Generally, average soil temperatures are starting this week in the mid to upper 40s across northern Ohio (Northwestern, North Central, and Wooster) and in the mid-50s across the south (Piketon and Western). With a significant warm-up anticipated this weekend, with high temperatures into the 70s across the state, soil temperatures should respond nicely.
Figure 1: Average daily air temperature (red), two-inch (green) and four-inch (blue) soil temperatures for spring 2020. Soil type and placement are provided for each location. Map of locations provided in the bottom right. Soil temperatures are minimum temperatures for Versailles and Xenia and daily average for other sites.
Figure 2 (left) shows another week of light precipitation across northwest Ohio, where most counties picked up less than 0.50”. Slightly heavier precipitation, up to 1 inch, fell across the rest of the state. This was generally 50-95 percent of normal for this time of the year. With persistent drier conditions in the west and northwest, the area of soil moisture in the 30-70th percentile range has expanded (Figure 2 – right). Very wet soil conditions remain across the east and south.
Figure 2: (Left) Precipitation estimates for the last 7 days ending on 05/11/2020. Figure provided by the Midwest Regional Climate Center (https://www.mrcc.illinois.edu). (Right) Calculated soil moisture ranking percentile for May 10, 2020 provided by NOAA's Climate Prediction Center (https://www.cpc.noa.gov/).
For more complete weather records for CFAES research stations, including temperature, precipitation, growing degree days, and other useful weather observations, please visit https://www.oardc.ohio-state.edu/weather1/. For a weekly climate assessment, visit https://climate.osu.edu.