In this study, the temperature, precipitation and groundwater level variations and changing patterns with varied time scales are presented for Taipei metropolitan area which consists of the capital city with neighboring counties. Along with the continuous city expansion during the past decades, global warming and heat island effect have generated perceivable negative impacts on environmental and reflect on the climatic and hydrological parameters. In addition to accelerating climate warming, hydrological extremity becomes more evident during the past decades and greatly elevates the risks of drought and floods in the study area. These observations in the Taipei metropolitan area support the common hypothesis that climate variability would increase as climate warms. The air temperature records, in conjunction with hydrological data, provide useful and invaluable information for the ongoing study of subsurface environmental changes resulting from nature and anthropogenic influences in Taipei metropolitan area. The continuing climatic warming and hydrological extremity would create observable impacts on the subsurface environment of Taipei metropolitan area and need to pursue in a fast and efficient pace.