We've been having that sort of night temperature for around a week now, and the Met Office says -10C for Perthshire tonight. Early this morning we had several more inches of snow, and the 10 inches that fell on the A9 between Glasgow and Perth shut the road for 9 hours. I'm in the low-lying area E of Perth, and we've probably not had the -16C but we have had continuous snow cover for a week and really cold nights - which has stopped me opening hives for the oxalic treatment.
Pete, Stonehaven should be above freezing by the end of the week but the forecast says that there will be a raw E breeze coming off the North Sea. Early tomorrow morning I'm taking the kids skiing at Glen Shee, just a few miles W of Loch Muick! Hope it warms a little for you by then (it should, but it will still be cold).
all the best
Gavin