It's 2:00 AM here and my wife and I just came thru Turtle Lake, WI a bit ago on our way home. The Endurance G-3120 turbine (69 foot diameter) on a 250 ft tower installed in the industrial park there was running.
When we got home all four of our turbines are running, fading in and out of cut-in, and my anemometer shows 6.2 mph from 178 degrees @ 74 feet.
I assume that map must be complied from surface observations at airports. I checked the last reported data from the local airport and they're reporting 0 mph at the surface and the wind map shows 1.2 mph for our latitude and longitude.
The wind at or above 30 meters rarely gets below 5-6 mph, except in extreme conditions where a high pressure area dominates a large portion of the earth.