A local area cosmogenic neutron sensor is used for detecting moisture within a measurement surface. A neutron detector is positioned on a stand structure holding the detector above a measurement surface. A moderator material and neutron shield are positioned around at least a portion of the neutron detector. The neutron shield substantially covers lateral sides and an entirety of a top of the neutron detector and is not positioned on a bottom side of the neutron detector. A thermal neutron shield is positioned below the neutron detector and in a path of neutron travel between the measurement surface and the neutron detector to substantially block environmental thermal neutrons from reaching the neutron detector, which improves the signal-to-noise ratio and signal contrast of the local area cosmogenic neutron sensor.