It is generally accepted in cultivation in the northern hemisphere that plants come out of dormancy around mid-February and enter dormancy around the end of October. The decreased photoperiod and a decrease in temperature in late October trigger the onset of dormancy. It is about the middle of February when the length of the days start getting about right for the plant to start growing again. However, growth will be slow until around early to mid-May, then plants will start growing more rapidly.
In many places in the United States, the weather outside in February is still too cold for the plant to journey back outdoors. It is best to find a sunny, south-facing window to put the Venus Fly Trap in to grow until there is no risk of frost or freezing. Once the frost and freezing risk is over, it is safe to take the Venus Fly Trap outside without any worries. Venus Fly Traps are best grown outside where they get excellent sunlight and have the ability to capture food to feed themselves.