Originally Posted by
stevepusser
The W to E winds are likely to be strongest in the spring...summer is when the SW US High builds up and can suppress those winds.
And in the midwest an east you can get tropic circulation coming out of the SE in July and August, causing headwinds for people riding east. We had many days of headwinds in IA, IL, IN and OH riding east on the Northern Tier route during the brutally hot and humid summer of '99.