Pollen counting typically begins in late March or early April once temperatures start to warm up and all the snow has melted
How are the pollen and mold counts determined?
The counts are performed under a microscope from pollen and mold samples collected by an air sampler on the roof of our office in Greenfield. Unlike some pollen websites, we do not use historical or predicted data in our daily counts ‐ they are actual observations made by one of our staff. Pollen is sampled during the 24 hours before counting, so sudden changes in weather such as rain or wind may produce changes in pollen levels not yet shown in the count.
Historical Pollen and Mold Averages
Our historical averages are calculated from multi‐day rolling averages using data collected since 1995. Due to variations in weather and count availability, we have found that the rolling average method produces much more meaningful average counts than the calendar of single‐day historical averages that we used to provide. For full season graphs and comparison of past seasons, visit the Pollen Explorer.