Thanks guys.
Any idea what Peet Bros use?
Those confirms what have been little our toughts on the finnish forum too that in fact in many cases there may be same sensor in different brands, and, what really matter in cold, clear weather are what closure the brands use for the sensor, what not may be the best for such conditions.
I use Davis, and have actually temps not close to the limit of -40C but its in north of the country where temps now stays below -30C