<p>A total of 180&#xa0;h of seasonal sampling surveys covering 60&#xa0;days were carried out from June 2020 to July 2023 to know the species diversity of moths in three ban oak <i>Quercus leucotrichophora</i> A. Camus (Fagaceae) forest sites in the Lesser Himalaya (LH) &amp; Greater Himalaya (GH) regions of Garhwal in Uttarakhand state in northern India. Three hundred and seventy-six (376) moth species belonging to 21 families, 51 sub-families and 222 genera were recorded from ban oak forests. The dominant family was Geometridae (124 species) followed by Erebidae (104), Crambidae (37) and Noctuidae (31), respectively. Species similarity was higher amongst the two sites, Chakrata and Mussoorie (LH) than Mandal (GH). The species richness and abundance showed two seasonal peaks annually during May (pre-monsoon) and September (early post-monsoon) months. Moth communities of the ‘pre-monsoon’ and ‘monsoon’ seasons had greater similarity than ‘post monsoon’ species. Moth community structure during the ‘post-monsoon’ season in ‘Mandal’ was determined to be the most distinct amongst all the seasons and sites sampled. Moths such as <i>Numenes patrana</i> Moore, 1859, <i>Fascellina porphyreofusa</i> Hampson, 1895, <i>Medasina basistrigaria</i> (Moore, [1867]) &amp; <i>Karana gemmifera</i> (Walker, [1858]) unique to this community were recorded. Species abundance of moths correlated positively with both temperature (<i>r</i> = 0.2682; <i>p</i> = 0.0039; <i>n</i> = 60) and relative humidity (<i>r</i> = 0.3034; <i>p</i> = 0.00050; <i>n</i> = 60) during the sampling period (April-November), being highest at 80–90% RH at 18-21^OC. A total of 130 species showed preference for only one season and 32 species amongst them occurred only during the ‘monsoon’ season indicating a univoltine and specialized lifecycle and short flight periods and strong seasonality in these forests. The study calls for conserving ban oak forests holding unique moth communities.</p>