Abstract-Bangladesh is one of the most vulnerable countries of the world to climate change. The magnitude and frequency of extreme events such as high intensity rainfall, flash flooding, severe droughts, etc. are expected to be altered in future as a consequence of this change. This can introduce an element of uncertainty in the design of hydraulic structures, urban drainage systems, and other water-sensitive structures, if the variability is not taken into consideration. This study aims at developing a regional Intensity-Duration-Frequency (IDF) relationship for Dhaka city for present as well as future climatic scenarios. The scaling properties of extreme rainfall are examined to establish scaling relationship behavior of statistical moments over different durations. The results show that a rainfall property in time does follow a simple scaling process. A scale invariance concept is explored for disaggregation (or downscaling) of rainfall intensity from low to high resolution and is applied to the derivation of scaling IDF curves. These curves are developed based on scaling of the generalized extreme value (GEV) and Gumbel probability distributions. It is seen that scaled estimates are relatively close to observed estimates.