Refractivity happens due to stratification in the lower boundary layer over oceans due to variability of moisture, temperature, wind and sea surface temperature which collectively may lead to generate evaporation duct. The evaporation duct has a significant impact on the spread of electromagnetic waves in the atmosphere over oceans. So it is of great significance to analyze and forecast evaporation duct based on the actual atmospheric and marine environmental data both from the meteorological and military point of view. This ducting sometimes support normal propagation of radar signals and sometimes may cause distortion and attenuation of signals depending on the height of evaporation duct. This leads to over-estimation and under-estimation of rainfall by weather radar. So, to get the exact picture of rainfall from the weather-systems coming from oceans (like tropical cyclones) is highly important in weather forecasting. The aim of this study is to locate evaporation duct so that results may be used in applying correction measures in radar meteorology for better rainfall forecast.