To face the challenge of mismatching between power supply and demand, building flexibility is required to schedule flexible loads and improve the coordination of power grids. Due to climate change, mounting evidence of extreme weather and climate event has been reported. Understanding the effectiveness of flexibility management strategies under different climate conditions is essential. Using the typical and extreme weather data of cities in five major climate zones of China, this study investigates the energy flexibility potential of an office building under three short-term HVAC management strategies, aiming to discover its effectiveness under different local outdoor climates in China’s context. The results show that the peak load flexibility and overall energy performance of the three short-term strategies were impacted by outdoor climate conditions. The peak load reduction rate of pre-cooling and zone temperature reset strategies declined linearly as the increase of outdoor temperature. In the extreme climate condition, the daily peak-load time was found to be over two hours earlier than that of the typical condition, and the intensive solar radiation in the extreme condition could result in a weak correlation between peak load reduction and outdoor temperature and risk of maintaining the comfortable indoor thermal environment.