The Rover Environmental Monitoring Station (REMS) will provide a daily report of atmospheric weather conditions on Mars, including atmospheric pressure, humidity, ultraviolet radiation from the sun, wind speed, wind direction, ground temperature, and air temperature. Water vapor observations will provide the first in situ measurement of near surface humidity, potentially yielding insights into surface-atmosphere exchange and atmospheric condensation processes. Finally, monitoring of changes in ultraviolet radiation - which will be the first ones to be taken on the surface - will provide important information necessary to assess the habitability of the near surface environment.