IntroductionMaritime Antarctic meltwater lakes are highly sensitive to atmospheric variability, yet their short-term hydrothermal responses remain poorly understood because most studies rely on seasonal or daily observations that cannot resolve sub-daily atmosphere–lake interactions.MethodsThis study investigated Yanou Lake, a shallow maritime Antarctic meltwater lake, using continuous 5‐min meteorological and hydrological observations collected over 66 days during the 2025–2026 austral summer. Wind speed, air temperature, atmospheric pressure, water temperature, and lake depth were analyzed using an integrated framework combining event‐based atmospheric forcing detection, lagged correlation, wavelet coherence, change‐point detection, and statistically validated threshold analysis.ResultsA total of 916 five‐min event observations (4.84% of the record) were grouped into 12 independent compound atmospheric forcing events. Cross‐correlation analysis identified weak but measurable delayed atmosphere–lake associations, while autocorrelation indicated persistence in water temperature (75.6 h) and lake depth (165.9 h). Wavelet coherence showed that atmosphere–lake coupling was intermittent and scale dependent, strengthening only during discrete atmospheric events. Event‐level analyses indicated that average lake responses were small and varied among individual events. Change‐point analysis identified repeated thermal and hydrological reorganizations, whereas statistically supported thresholds of 6.22 m s -1 (wind speed) and 2.41 °C (air temperature) were associated with changes in lake behaviour.DiscussionThese findings demonstrate that atmosphere–lake interactions in Yanou Lake are governed by delayed, episodic, and nonlinear processes rather than persistent atmospheric control. The proposed high‐frequency analytical framework provides a transferable approach for investigating short‐term hydroclimatic dynamics in Antarctic meltwater lakes and improves understanding of cryosphere–hydrology interactions under ongoing polar climate change.