Daily and seasonal pollen forecasting for Halifax, Nova Scotia, Canada

Daily and seasonal pollen forecasts are important to allergists for diagnosis and patient care. Forecasts allow sufferers of asthma and hayfever to avoid exposure to high allergens levels and to plan activities during anticipated low allergen levels. Airborne pollen has been monitored in Halifax, Nova Scotia since the summer of 2000 as a joint experimental project between Environment Canada, St. Mary’s University, and the Lung Association of Nova Scotia. Aeroflora is sampled daily from mid-April to mid-September using a Burkard seven-day volumetric pollen and spore trap. Forecasts are based on the pollen count for the past 24 hours in combination with forecast meteorological conditions provided by Environment Canada.

While daily forecasts have proven beneficial to allergists and patients, a need was expressed for the creation of a pollen calendar specific to Halifax. Such a calendar, constructed from archived data, allows local allergists to better diagnose their patients, and patients to better self-manage their symptoms. Preliminary seasonal pollination trends indicate delayed onset as compared to the phenological model for the US Eastern Seaboard. In Halifax, hardwood pollination begins in mid-April, succeeded by the onset of softwood pollination in early-mid summer. Pollination of grasses and weeds occurs from mid-summer to the early fall. The date of pollination onset for each species will need to be monitored and adjusted as climate trends in the Maritimes dictate.