Differential frost heave between fine (earthy) and coarse (gravelly) domains was monitored over 10 years (2013-2023) on a mountain-top flat ground subjected to both frequent diurnal and deep seasonal freezing. Monitoring objects include, ground heave, soil temperature down to 55 cm, soil moisture, air temperature, rainfall, and snow depth. The two domains, differing only in the presence of uppermost platy gravel about 1 cm in thickness, undergo frequent diurnal frost heave with about 1-cm-thick needle ice formation. Annual frequency and cumulative amount of frost heave are not significantly different between the two, but the fine domain is slightly more active particularly in spring when the near-surface soil at just above 0 degrees C permits rapid frost penetration. Differential heave mainly occurs as a time lag in the start and peak of heaving, on average, by about 1 h preceded at the fine domain, which tends to concentrate stones to the coarse domain. Frost heave activity shows a large interannual variation, primarily depending on the duration of snow-covered days. Frost heave activity also roughly correlates with annual mean air temperature, possibly reflecting a decrease in snowfall days.