Thermokarst ponds in high latitudes are important methane (CH₄) sources in summer. Meanwhile, these ponds are ice-covered for around 60 % of the year and can accumulate CH₄ in the ice and within the underlying water column, which potentially results in high emissions during the ice-off. Here, we present data on wintertime CH₄ storage of ponds located within two peat plateaus in Northern Norway. Our results show that the wintertime CH₄ storage can contribute up to 40 % to the annual CH₄ budget.