Is the pollen season the same from year to year?

Not exactly. The beginning and end of the grass pollen season depends on the previous year's weather (how much grass is growing) and current weather (how much grass is flowering). This graph demonstrates year to year variation in the grass pollen count in the Campbelltown region. The bar graph demonstrates variability in the start and end dates of each year's season.The date of the peak count for each year is shown as a diamond on the bars.