<p>Landslide fissure investigations are crucial for assessing landslide hazards and understanding landslide kinematics. In recent years, unmanned aerial vehicle (UAV) airborne infrared thermography (IRT) has been used experimentally for landslide fissure identification. However, quantitative research on the thermal infrared characteristics and response patterns of loess landslide fissures is lacking. In this study, the thermal infrared characteristics and thermal response patterns of loess fissures over a 24-h period were investigated for the first time, using the Chenjia loess landslide group in Heifangtai Terrace as an example. Continuous monitoring revealed that the temperature of the loess landslide fissures varied sinusoidally throughout the day. Thermal anomalies were most pronounced between 3:30 am and 5:30 am (before sunrise), and the slow fluctuation in temperature differences was a key indicator for distinguishing fissures from intact loess. Fissures characterized by small widths, shorter lengths, and fill materials presented rapid temperature peaks, high peak temperatures, and large daily temperature differences. Conversely, width and length have little effect on the time required for the fissure to drop to the valley temperature. Additionally, the UAV shooting azimuth significantly influenced the IRT characteristics of the fissures, with the most pronounced temperature gradients observed in images taken at an angle perpendicular to the fissure strike. This study successfully demonstrates the potential of UAV IRT technology in probing the spatial distribution of loess landslide fissures and systematically summarizes the thermal response law of loess fissures.</p>