Knowing the start and ends dates of a pollen season is imperative in treating allergies. This graph is an example of how start and end dates vary dramatically from year to year based on weather, environmental conditions and human interruption. This information help allergy sufferers in regulating activities, taking action to minimize impact of allergens on their health and assists practitioners in letting patients know when to start their medication. Join our pollen alert program to get your daily pollen forecasts and to be alerted as to when the season has begun.