Yesterday I posted about insulating my cold frame to make it frost resistant, but also warm enough to bring on seedlings (and maybe even propagate seeds).
I left a min/max thermometer in the cold frame overnight and the results were very good.
The readings show that the peak temperature inside the frame was 26C (at mid afternoon on a clear 9C day) and the minimum temperature inside the frame was 14.9C (outside temperature dropped to 2C overnight).
The previous night, when I left the thermometer in the non-insulated cold frame with the paraffin heater turned on the minimum temperature reading was -0.3C with outside frosty temperature of -3C.
So, the insulating of the cold frame has worked very well.
I may have to make a more permanent lid to put over the cold frame at night as the one I lashed together yesterday could be susceptible to wind.