The temperature dependence of the H-2 NMR spectra in the deuterated pyridinium head group was measured in a lyotropic liquid crystal of an 85 wt % dodecylpyridinium iodide-water system. It was shown from the quadrupole splittings of three nonequivalent H-2 sites that "the motionally averaged inclination angle" of the pyridine ring increases by ca. 6 degrees on heating from 24 to 40 degrees C.