Yes, but it definitely is not too late yet. You can introduce them anytime prior to the end of fall flow, in my opinion, as long as you are willing to feed like mad during dearth or after fall flow to make up the difference. Others here on the forum who live in your area can tell you when the fall flow is/how long it runs.
In NC, I have done a split including frames of honey in the last week of June (right in the beginning of our long dearth here) and, without feeding, brought them through the winter. This year that same hive tripled in size in 2 months and provided me another two 7-frame splits last week.