As days get shorter, any moisture you do get will go much farther. Seed will also wait for rain on dry soil. There is a chance of getting just enough rain to germinate, then turning dry again. That would let seedling dry up.

At a certain point, usually about 2-4 weeks before your first avg frost, it's time to take your chances. Hold on the fertilizer until after germination if you want to minimize your risk of loosing money.