Bread-Bakers v104.n051.15

Ihave been making bread since March of this yer. I use a bread maker to 
mix, knead and make the dough rise, then I bake it in the oven. I haven't 
changed the recipe in any way but it doesn't rise like it used too. I've 
bought new yeast, same brand and type and still the same results. I live in 
CT and am wondering if the dry air here now because of the Fall versus the 
humidity of the Spring and Summer would make the difference?

Thank you,
Rudy