The level of nonlinearity in the dynamics of the daily mean air temperature data series over Michigan Grate Lake has been examined using appropriate statistical tools. The time series is collected from the database of Tides and Currents under the National Oceanic and Atmospheric Administration (NOAA), Menominee, MI, Station ID: 9087088, length 1584 days from 14th March, 2011 to 14th July, 2015 for this purpose. The raw data has been pre-processed using simple exponential smoothing and discrete wavelet transform (DWT) based denoising. To gauge the extent of nonlinearity under the dynamics of the test series, delay vector variance (DVV) strategy is applied. The study yields that the fluctuation of daily mean air temperature over Michigan Great Lake poses deterministic, regular, non-linear behaviour in the temporal domain.