Whelp, for about 3 weeks I can wear a jacket without an overcoat, then it gets too hot to wear a jacket comfortably (so I opt out since I work in a business casual environment).
In the fall, there's about a month where I can get by with a jacket without an overcoat. Maybe two months if I wear UNIQLO heattech (a long sleeved undershirt).
I miss Texas. Summers were brutal, but you have 6 months of amazing weather October through March.