Wind speeds near the ground peak in the early afternoon. Higher altitude winds peak at night, but you need quite a large turbine to catch those. Sometimes there's no wind for days at a time.
Quoting from your link: "It is found that daily extreme wind speeds at 10 m are most likely in the early afternoon, whereas those at 200 m are most likely in between midnight and sunrise"
Ground is irrelevant; there's a reason why wind turbines are being put on top of tall towers.
