How many days before skin sensation recovers after hair transplant surgery? FUE method

It may take several weeks to months before the sensation on your scalp returns to normal.  It is different for every person.

Usually the sensation to the skin returns with a week or so but may take longer. In the donor area with an FUE it can depend on punch size, number of grafts harvested (or area between punches), difficulty of extraction, duration of swelling under the skin, age, or health status (as it relates to wound healing). If you had grafts placed in the front, that skin sensation usually returns quickly. The donor area may be more prolonged in recovery of sensation as even with the smallest punch, the cumulatively scar tissue in back is greater than the recipient area (due to the size of the site making tool vs the size of the punch). Eventually all ends well but make sure to have regular checkups with your surgeon to track your progress. 

Sensation loss remains just after surgery and it is "normal" to stay for months.That numbness may fade away in a long time up to 4-6 months . 

When there is surgery behind the forehead, there are small nerves that are traumatized and these will usually get their feeling back in a week, but some people take a few months