Global warming is the greatest environmental challenge facing the world today. It is broadly recognized that Bangladesh is very vulnerable to this problem. Indeed, it has internationally been argued that Bangladesh, as a country, may suffer the most severe impacts from global warming and climate change. The effect of global warming on Dhaka city is likely to severe. The green house gases emission ratio of Dhaka city is negligible comparing to worldwide ratio. But this contribution is likely to increase rapidly with the continuing growth of the city's population. At the same time, Dhaka is prone to damaging and costly flooding, both from the rivers that bound it and from rainfall that generates runoff that is beyond the capacity of the drains. Annual mean temperature and rainfall and humidity data are used to realize the global warming effect of the study area. From the data analysis it is found that temperature and rainfall are increasing day by day as well as local weather and climate is changing. Urban flooding, water logging, reducing fresh water availability, warmer and more humid weather leading to crisis food security, and health of the city dwellers.