Allergies

How we forecast pollen

Pollen forecasts are generated using machine learning, combining actual pollen observations, years of historical data, and weather conditions (like wind, rain, and humidity) to predict pollen levels in your area. Forecasts may vary from conditions at your specific location.

Pollen Count

The daily pollen counts shown on the Allergies page reflect estimated average pollen levels for the day, helping you stay aware of pollen conditions in your area throughout the day.

How We Measure

Pollen count measures estimated local pollen concentration in the air, expressed in grains per cubic meter (grains/m³). Picture an invisible one-meter box of air; the count represents the estimated number of individual pollen grains in that volume of air for the relevant area.

Pollen Level

Our four pollen levels are based on the National Allergy Bureau™ (NAB™) guidelines:

Low
Unlikely to be associated with symptoms for most people, except those with severe allergies or respiratory conditions.
Moderate
May be associated with symptoms for some people, especially those with allergies or respiratory conditions.
High
Likely to be associated with symptoms for people with allergies or respiratory sensitivities.
Very high
Very likely to be associated with symptoms for many people, including those with mild allergies.

Historical Pollen Counts

As tree, grass, and ragweed pollens peak at different times, most locations experience three distinct allergy seasons. This chart shows those monthly trends for your location using average pollen counts from over a decade of historical data.

Important Notice

This allergy, pollen, and weather-related information is provided for general informational and planning purposes only and is not medical advice, diagnosis, or treatment. Pollen levels, forecasts, historical trends, and risk categories may not reflect your individual health condition, exposure, or symptoms. Consult a qualified healthcare professional for medical advice, diagnosis, treatment, medication decisions, or concerns about allergies, asthma, or other respiratory conditions. If you experience severe symptoms, difficulty breathing, or a medical emergency, seek immediate medical attention.