Bay Area allergy season after the drought: "It’ll be bad".
The Bay Area’s allergy season is nothing to sneeze at.
"A ton of rain produces a ton of pollen," he said.
Reid says local trees begin pollen production in early February and continue until late April, while grass pollen occurs around mid-April and disperses mid-June.
According to Reid, "there are two different ecosystems for allergies in the Bay Area: San Francisco and the rest."
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The plants that cause allergies, however, are pollinated by the wind.
Early in the season, wind-pollinated Monterey cyprus trees are most often to blame for runny noses in San Francisco, while oak trees often aggravate those in the East Bay.
These visual cues are more trustworthy than pollen counters whose numbers vary with the wind, Reid says.
In fact, Reid notes there is no pollen counter in San Francisco, so websites and widgets often get their data from neighboring cities, like San Jose and Pleasanton.