Most vehicle manufacturers recommend replacing your cabin filter at least every 2 years. This could be more often if you live in highly polluted areas or drive in the city. If you drive a lot on unsealed roads or commute on roads with lots of trucks you may also need to get your filter changed sooner.
When the weather is cooler, this is usually the ideal time to replace your pollen filter. With the warmer weather comes an influx of pollen and allergens. Changing out your filter in Winter will have you prepared when Spring and Summer come around.