The planetary boundary layer (PBL) is the lowest part of the atmosphere, reaching up to about 2 km above the ground, and is strongly shaped by surface conditions. A key feature of the PBL is the low-level jet (LLJ), a fast-moving wind that forms at night close to the surface. LLJs are important because they transport moisture and energy, influencing weather and climate. In the Southern Great Plains (SGP), most studies have focused on LLJs during summer, but their year-round behavior and seasonal variations are less understood. To better capture LLJ events, we use high-frequency data from Aircraft Meteorological Data Relay (AMDAR), which provides more frequent observations than traditional weather balloons. Our analysis shows that the strongest LLJs are linked to a warmer but shallower boundary layer, while moderate LLJs form under warmer and deeper conditions. In spring and summer, strong LLJs are associated with colder but less stable nighttime layers. We also found patterns in wind rotation that point to the role of inertial oscillations and mountain–plain breezes in shaping LLJs. These results show the value of combining multiple data sources to better understand PBL processes and their seasonal changes.