Namundag sa Andover, Hapshire, Inglaterra, kan 1966, si Wilmhurst nakakua nin BSc sa environmental science sa Unibersidad nin Plymouth kan 1988. Dangan natapos nya an sarong PhD sa Unibersidad nin Canterbury kan 1995, na may thesis tituladong A 2000 year history of vegetation and landscape change in Hawkes Bay, North Island, New Zealand, na pinamahalaan ninda Vida Stout asin Matd McGlone.