Knowledge of climate dependency of building energy consumption is useful for predicting the impacts of climate change and urban heat island on energy demand and associated carbon emissions, and to evaluate and improve building energy performance. Climate dependent electricity consumption is examined in this study for four office buildings in Adelaide, the capital city of South Australia with a warm-summer Mediterranean climate. Influences of both outdoor temperature and specific humidity on building electricity consumption are analyzed using the multiple linear regression, based on both sub-daily and monthly electricity consumption data. The results indicate that there is a daytime mean temperature threshold of around 17. °C, above which, electricity consumption increases with air temperature. Specific humidity also contributes to interpreting the temporal variability of office hour electricity consumption. Daytime temperature and specific humidity together determine 80-90% of office hour electricity consumption variation for days with mean daytime temperature above the threshold temperature. Office building daily electricity consumption can be examined with monthly electricity consumption data of a period of three years. The results also suggest that heatwaves may increase office building electricity demand by up to 50%, and that one degree warming can increase annual office electricity consumption by 2% in Adelaide.