When the rain arrives, it comes with refreshing, rain-cooled air.
What we don’t give much thought to is the bonus of the cooling effect of rain on soil temperatures. Wednesday, October 5, 2016 gave us a good example of how rain cools the soil.
Tuesday evening the Minco Mesonet site recorded 0.7 of an inch of rain. South of Minco, at the Chickasha and Ninnekah Mesonet sites no rain was collected.
The peak four-inch bare soil temperatures on Wednesday afternoon showed a significant difference between the sites. Minco’s high soil temperature was 79 degrees F. Chickasha hit 87 degrees F and Ninnekah 85 degrees F.
The Wednesday afternoon high air temperatures were similar between the three Mesonet sites. Pointing us back to the rain as the difference maker between the three sites. Minco’s afternoon high was 89 degrees F. Chickasha and Ninnekah both had maximum air temperatures of 91 degrees F.
We can also see the rain cooling effect on a graph of the 4-inch bare soil temperature. At Ninnekah the soil temperature went above eighty degrees each afternoon from Saturday through Tuesday. On Wednesday afternoon, it peaked above 85 degrees F.
Minco had a peak over 85 degrees F on Sunday afternoon. Both Tuesday and Wednesday, the peak afternoon soil temperature was below eighty degrees F. Tuesday’s cooling was from lower sunlight levels from the storm clouds. The rain began at 7:00 PM that night. Wednesday it remained cooler from the cooling influence of higher soil moisture.
The 0.7 of an inch of rain at Minco provided some welcome water and cooler soil too. Winter wheat and canola will respond to that rain and a cooler soil with a nice jump in growth.