April is our windiest month on average in Minnesota. If you add up all the hourly wind readings in the Twin Cities for April you get 12.3 mph. That makes April tops for wind, with March and May tied for second at 11.3 mph.
As you might expect, July and August are the most tranquil months. Balmy summer breezes average only about 9 mph.
The prevailing wind direction in April is from the north. But starting in May, the prevailing winds blow from the southeast to south and stay there until October. The winds of April mark the seasonal changes that are about to occur. Wind is caused by temperature and pressure differences in the atmosphere. These differences are greatest in spring in the Upper Midwest.
They call Chicago the "Windy City" but did you know the Twin Cities has a higher average annual wind speed than Chicago? We average 10.6mph annually, compared to a mere 10.3mph for Chi-Town.