Pollen Alerts For Keystone, SD

Pollen Index: 10.6 Pollen Level: high Predominant Pollen: Ragweed, Nettle and Sagebrush/Sage. The quantity of pollen grains in the air for Tuesday will be falling but will remain in the very high range. Since the weather has a major influence on pollen dispersal, this decrease is due in part to falling temperatures, higher dew points and lack of strong winds.