March is one of my favorite months-still cold enough for skiing, and the sun is up later and later. It is a much cheerier month than December. There are all kinds of poems and stories attesting to the windiness of March 9like Houseman’s “mad March Days”).
But, is it true that march 9in the northern hemisphere) is the windiest month?
I think you’d have to define what you mean by windiest carefully. There are no (or at least almost no as I don’t recall any) hurricanes in March so it’s unlikely March holds the record for highest recorded wind speed any place in the Northern hemisphere that experiences hurricanes.
I looked up my home town of Springfield, Illinois on www.city-data.com and I’ll be damned, March is the windiest month. I wonder if the fact that March is a busy tornado month is a factor? 
And now I’ll look at some random cities across the US:
March is the windiest month in Kissimmee, FL.
It’s a tie with April in Oklahoma City.
March takes second place to April in Knoxville, TN.
March and April are tied in Seattle, WA.
March is barely in the running in Pasadena, CA.
From a meteorological standpoint, it makes sense that March/April are the windiest months in the U.S. (which you can seem to glean from the city wind data, according to the U.S. averages).
The jet stream is the strongest during those months, with spring sun angles/heating beginning to develop, and cold winter arctic outbreaks still possible, resulting in strongest nonrth/south temperature gradients. Mid/upper atmospheric temperatures are colder than in the autumn. All this leads to stronger storm systems generally, resulting in stronger pressure gradients, and stronger winds on average across most of the U.S. east of the Rockies.