During the warm part of the year, weather forecasts sometimes include more than just weather information - you might also get pollution forecasts, forecasts of ultraviolet ray intensity, and - for you allergy sufferers - even pollen forecasts.

These pollen forecasts are based on computer models that combine several types of data: current pollen measurements from a national network of stations; historical pollen records from across the country; and finally current weather information. Weather variables that affect the pollen forecasts include temperature, humidity, wind, and whether or not rain is likely.

Here are two web sites to get pollen and general allergy information. Take a look at aaaai.org - that's the American Academy of Allergy, Asthma, and Immunology. Pollen forecasts out to four days can be found at simply pollen.com.