I'm assuming you're somewhere that is getting quite cool this time of year. How about pumpkin/apple picking, a drive/wagon ride to look at the turning Autum leaves, have a campfire and roast hotdogs on sticks, go to a farm to look at animals, ummm I'll get back to ya if I can think of anything else :~)
Most libraries have a free story time (even for babies). Many parks and rec centers have an "open gym" time for families to let the little ones play together (in Portland, there are some for newborn to 17 mos, up to 5years, etc. They pull out the appropriate balls, scooters, etc. for the kids to play on. It's a buck.) I love my play group, which I found on meetup.com. Learned about many places to take the kiddo.