Center of the chip is just starting to defrost at 5° after dropping it to 0° first for a few minutes.
Update: @ 10° there is a circular spot about 2/3 the size of the chip clear now. It is quite strange, the frost clears in a perfect circle but not quite centered on the chip.
Update 2: current ambients
Temp: 19.3
Dew point: 13.3
RH: 65%
Camera temp: 15° Chip itself is clear but a ring of frost can still be seen on the glass window.