16th September 2013 - Cold Frame Temperature

Middle lid closed, side vents open over night.

Last Nights inside Low   = 8.3 degrees C  last night       
Yesterdays inside High = 20.8 degrees C Yesterday

                Actual inside = 8.8 degrees C at 6:30 am 
              Actual Outside = 7.5 degrees C at 6:30 am

So the cold frame appears to provide about 1.3 degrees C improvement on external temperature with the vents open at 6:30 am. It makes me wonder what the difference as the lowest external temperature during the night?

Tonight I will try with the vents shut during the night and take more readings when I get home from work and before I go to bed and then again in the morning to try and see just how effective the cold frame actually is before I think about installing bubble wrap and foil etc.
 
Anticipated High Today on the BBC Weather web site for my post code =12.0 degrees C