packable jacket (flying from here and ending up in Toronto in October will be a cold shock for ya!) (Something like Sierra Designs Microlight Anorak)
Possiblity of a sweater/fleece (this is low priority item)
Consider combining these. My current weather gear is a four way system of a shell with a zip in, reversible liner. Spring & Summer, I use the shell for rain. Fall & Winter, the liner can be used alone or combined with the shell. Pack the liner & wear the shell to cut down on packing space.
Edit: spelling