A wireless sensor assembly for monitoring conditions in an ambient environment, such as for use in a climate control system for a data center is disclosed. The sensor assembly has a small form-factor housing extending along a longitudinal axis and defining an interior space. A sensor circuit is disposed within the housing and includes at least one sensor element for detecting temperature and/or humidity that is enclosed within a vented sub-chamber of the housing. A mounting member forming part of an exterior surface of the housing mounts the sensor assembly vertically along the at an installation location within an ambient environment being monitored.