Can anybody tell me what a normal ground temp at 6' below the surface would be in the Fox Valley area of Wisconsin would be for mid July? Only reason I ask is after my system had not been running for a few days, I would have expected a larger drop in EWT that what I saw. When the system is running, I typically see 71-72 degrees, after not running for two days, it only dropped to 70 when the system was turned on again. This probaby is normal, but was just courious. I have a horizontal closed ground loop, non slinky, buried at six feet. Not sure of the total length but was told it is a 5 ton loop with a 4 ton geo unit.