#1 Never Lay Concrete On Frozen Ground
The key to laying concrete during the winter time is to never lay it when the ground is frozen or on top of snow or ice. When you lay concrete on frozen ground, the coldness will transfer to the concrete and will slow down the drying process. Additionally, when the ground thaws, it will settle and expand, which will cause the concrete to crack.
#2 Warm Up The Ground Before Laying Concrete
If you want to lay concrete during the winter time, you need to take the temperature of the ground. If the ground is frozen, you need to warm it up