Have there been any allergies (plants, trees, etc.) identified as occurring between early october and early november in the san francisco bay area?

Grass: Fall weed pollenation typically concludes by the end of sept however, late rains can result in a second wave of grass pollenation. Rains and warm weather can also result in high mold in the air. Go to pollen.Com for local pollen counts in your area.

Weeds: Weeds tend to be a fall allergen....So weeds could also be the problem. Grasses and weeds are similar but different and definitely pollinate at different times.