A portable device for checking wind direction discharges a visible, and optionally scented, vapor stream into the atmosphere in a well-defined reference direction. In some embodiments, the device includes a power source, a vessel having an internal plenum chamber storing a volume of air, a reservoir containing a vaporizable agent, a vaporizing element associated with the vaporizable agent, and a pressure switch. The vessel is deformable to generate an airflow that operates the pressure switch to temporarily connect the power source to the vaporizing element, thereby energizing the vaporizing element to generate vapor. The airflow also carries the vapor into the atmosphere as a visible vapor stream flowing in the reference direction. The reservoir and vaporizing element may be carried in a cartridge removably mounted on the device. Other embodiments operate similarly, but use alternative means for generating gaseous flow to operate the switch and/or carry vapor into the atmosphere.