Variability of annual daily maximum rainfall of Dhaka, Bangladesh

• This paper highlights rainfall characteristics of Dhaka City.
• Statistical analysis was performed to 57 years (1953 to 2009) daily rainfall data.
• We applied Gumbel and normal distribution function.

This paper deals with a study on rainfall characterises of Dhaka, the capital city of Bangladesh for the period of 1953 to 2009. Data were collected from Bangladesh Meteorological Department in January 2011 and found 2.84% missing data. Descriptive statistical analysis was conducted on annual rainfall, annual daily and monthly maximum rainfall. We applied Gumbel distribution function to estimate return periods of extreme rainfall events and found that annual daily maximum rainfall equal or greater than 425 mm had a return period of 100 years. Normal distribution function was adopted to forecast rainfall variability due to global climate change and found that annual daily maximum rainfall equal or greater than 200 mm might occur in any 12 years during the period of 2010 to 2066. The outcomes of this paper can be used in better understanding rainfall patterns of Dhaka, Bangladesh.