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Based on the ensemble empirical mode decomposition method, this study explores the differences and similarities in multiple time-scale characteristics of summer air temperature (T) and equivalent temperature (T-e) over China during 1961-2017, using daily meteorological observations collected at 412 stations in China. Their relationships to global sea surface temperature variations is also discussed. Results show that both T and T-e can be decomposed into five components, which includes multiple timescales, from interannual to long-term trends. The spatial patterns of each timescale's leading mode show that the variations of T-e are generally larger than that of T. Meanwhile, both T and T-e are dominated by their inter-annual, multi-decadal variations and the non-linear trend. High correlations of T and T-e can also be found in these major scales. The related sea surface temperature variations in these major scales also show consistent patterns, which correspond to El Nino-Southern Oscillation, Atlantic Multidecadal Oscillation and the global warming trend in the sea, respectively. In other scales, both spatial patterns of T and T-e and the corresponding correlation patterns with sea surface temperature are distinguishable. The current results explore the compound changes of surface temperature-humidity during the past five decades from a new perspective, which provides some insights for a better understanding of the possible causes of climate change over China.