As the snow turns to mud this week, this is a good time to advertise links for the soil temperatures in Illinois. The Water Survey operates a 19-station network of sites around the state collecting hourly soil temperatures at 4 and 8 inches under grass as well as an estimate under bare ground.
All this information can be found at the Illinois Climate Network Soil Data site. Below is just a screenshot of that page to show where you would find that information on the real web page.
Here is a snapshot of 4-inch soil temperatures as of 10 am, March 13, 2015. Soil temperatures are still near the freezing mark in the northern half of the state, but warm into the 40s and low 50s in the southern half of the state.
The Illinois State Water Survey maintains a network of 19 soil temperature sites across the state that measure temperatures at 4 and 8 inches. You can look at maps for
10 am, any hour of the day, high for the day, low for the day, under sod, and under bare soil. You can find all their data at this site: http://www.isws.illinois.edu/warm/soiltemp.asp
Here is the 4-inch soil temperature from yesterday.
It’s always a day behind so that they can upload the data and do quality control checks. The data now arrive hourly. My mistake – they used to upload the data once a day and do QC but now it is more timely. As you would expect, soil temperatures change more slowly than the air temperatures.
And here is what it looked like two years ago after a record warm March. I chose April 2, 2012 for the same time of day and depth. As you can see, the soil temperatures were about 12 degrees warmer and USDA NASS reported that 5% of the corn crop had already been planted by that date.