When does the frost melt? (warm, temperatures, Chicago, night)

[Joe90]

i had a discussion on another thread recently, regarding frost and frozen ground. I mentioned that in some conditions, frost will remain unmelted in sunny conditions at temps of about 12C/54F. This happens under stable high pressure with low dewpoints (by the local standard) on S or SE slopes or on flat ground where there is a shadow more than a few inches high. The preceding night would be in the -2 to -5C/28-23F range.

What about where you live? Does frost linger in sunny, mild conditions?

[chirack]

I live in Chicago and the terain around here is as flat as an pancake. Frost does not linger in sunny mild conditions but it can frost at night from October to April with hard frost(frozen ground) from about Late November/December to Early March. It does take the Ground a bit longer to warm up vs. the air but not by much. Shade at 54F combined with thoose kinds of low night time temperatures would keep frost around a tad longer.