Recent studies predicted warmer and wetter summers in high latitudes in the future. An increase in precipitation and temperature in these regions will affect the thermal processes in the soil and, as a result, methane fluxes. We used an experimental approach to evaluate the research question: how wide is the range of responses of microbial assemblages in the methane cycle to increased precipitation under current conditions and projected changes? In the maritime Antarctic ecosystem (Fildes Peninsula, South Shetland Archipelago), we measured the soil methane fluxes and methane emission/uptake in the field manipulation experiments with additional precipitation. The soil methane fluxes from the surface of various landscape units of the Fildes Peninsula was measured at 16 monitoring sites. It was pointed out that the soils demonstrated methane-uptake capacity throughout the season (January–February 2022), which varied from − 42.04 to − 0.71 μg CH4 m−2 h−1 and was most pronounced in early January, gradually decreasing toward the end of February. In field manipulation experiments, the response of soil methane flux to increased precipitation was studied. Dynamic measurements of methane emission/consumption were carried out using a gas analyzer Picarro G4301, in two soil types: Protic Arenosols (Turbic) and Skeletic Turbic Cryosols, on selected sites: (i) control plots (no additional rainwater); application of additional rainwater in the amounts of (ii) 5 mm m−2, (iii) 10 mm m−2 and (iv) 15 mm m−2. We found that the Protic Arenosols (Turbic) were in equilibrium in terms of the emission/consumption of methane, while the Skeletic Turbic Cryosols showed a pronounced ability to oxidize CH4. The supplement of an additional 90 mm m−2 of rainwater did not affect the ability of Protic Arenosols (Turbic) to oxidize methane but moved the oxidizing capacity of Skeletic Turbic Cryosols soils toward methane emission.