By: Aaron Wilson, Greg LaBarge, CPAg/CCA, Elizabeth Hawkins, Sam Custer, OSU Extension
We are once again providing a soil temperature overview in the C.O.R.N. Newsletter through April-May 2020. The College of Food, Agricultural, and Environmental Sciences (CFAES) Agricultural Research Stations located throughout the state have two- and four-inch soil temperatures monitored on an hourly basis.
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.
Our Western site in Clark County is now available. We have added this and Northwest Agricultural Research Station from Custar, Ohio as well. We are still supplementing additional data from western Ohio with data from Darke and Greene Counties. These sites (noted by an asterisk on Figure 1) report minimum (morning) soil temperatures. The other sites are reported on Figure 1 as a daily average.
Figure 1 shows that two- and four-inch soil temperatures have cooled significantly in response to air temperatures running 4 to 12°F below average for the week ending April 19, 2020. In general, average soil temperatures have dropped from the mid-50s/low-60s back into the 40s across the state. In fact, 2-inch soil temperatures at Northwest were in the upper 30s as of April 16, 2020. These soil temperatures are below their 5-year averages. The current weather forecast calls for seasonally cool air temperatures over the next 5-7 days with highs generally in the 50s and 60s, and overnight lows in the 30s and 40s. Soil temperatures are likely to slowly warm throughout the week.
Figure 2 (left) shows that lighter precipitation fell across Ohio this week, but some of this precipitation across the north came in the form of accumulating snowfall. Totals ranged from 0.1 inch in the northwest up to 2 inches in southeast Ohio. Calculated soil moisture ranking percentiles (right) remain above the 80th percentile with the greatest percentiles noted in southeast Ohio.
Figure 2: (Left) Precipitation estimates for the last 7 days ending on 4/20/2020. Figure provided by the Midwest Regional Climate Center (https://www.mrcc.illinois.edu). (Right) Calculated soil moisture ranking percentile for April 19, 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/.