Even though weather systems often go west to east, for much of the middle of the USA, winds are more often from the
south than the
west.
This
Wind History Map shows wind frequency by direction, for each month. Each pie slice is the percentage of wind from that direction.
Click the month slice at the top right. If you then click another month, it displays the average of all selected months--a bit confusing at first.
Click a station to see it's wind directions in blue and wind intensity in red.
You can drag and zoom the map, then bookmark that view.
For example,
Des Moines IA in July.
East is actually more likely than west! S, SE and SW are the most common that month.
And SW and N winds are somewhat stronger than E or W winds, and all are in the 10 knot range.