We can get a minus 8 here but I am sure that our daytime temperatures are warmer than yours allowing the frost to lift and things to thaw out. We rarely get snow except on the surrounding hills. A minus 8 here is going to be associated with a very heavy frost and almost inevitably a sunny day with a perfectly blue sky. The point is that the racing surface here is never going to be frozen, at least from 12 noon to 12 midnight.