[MrBig46]

This morning I went to the garden to check how is my tomatoes in greenhouses. Uncomfortable cold 1 ° C and the wind 40 km per hour. I measured temperature in the cold frame (6 ° C) and in the hothouse (8 ° C), the differential was only 2 ° C. However, the difference between tomatoes is quite noticeable (pictures). But this may not be the only air temperatures, but in the hothouse tomatoes fertilized with horse poop and rotting leaves, the soil is certainly warmer. But even so, in a cold frame tomatoes grow well and they will certainly mature much earlier than that in normal planting dates after May 15.
I measure a temperature by DataLogger only in a cold frame. Last week, the frame was permanently closed. The outside temperature is the graph of meteorological stations, 2 km from my garden.
I came home pretty frozen, now the wind speed dropped by some 5 km / h, but the snow falls.

Vladimír