What factors affect the daily pollen count?
A number of factors affect the daily count, including daily fluctuations in temperature, wind conditions, humidity and precipitation, and of course the biology of the grasses themselves.
Most temperate grasses flower in late Spring and early Summer. Subtropical grasses may also flower throughout summer and autumn with bursts of grass production boosted by summer rainfall. During the flowering season, weather conditions such as wind and humidity will also affect how much grass pollen is in the air.