NDAWN, the North Dakota Agricultural Weather Network, not only monitors the weather, but also monitors soil conditions. The soil temperatures are probably used the most during the spring planting season, but the temperature data is also quite valuable this time of the year. NDAWN has approximately 50 stations with soil moisture probes that go down 1 meter in to the soil. Which is about 40 inches. Those sensors also measure temperature. Besides the soil moisture sensors, NDAWN also has deep temperature probes that go down to about 7 feet. In turn, you can find out the frost depth is averaging about 2 feet right now although some locations the frost is down to 40 inches.