This study uses 3600 radiosonde profiles obtained by experimentation from four stations situated in Egypt within 2015–2016 period and Bevis linear regression method was applied to develop a new water vapor weighted temperature (Tm). Bevis, Schueler, Yao, Liou, Suresh Raju and Wayan models performances are assessed using the Tm estimated in this study. The biases of these six models were found to be 4.64 k, 10.12 k, 4.46 k, 4.64 k, 4.14 k and 11.53 k, respectively. Three others radiosonde stations data were used to test the estimated Tm and the above six Tm models, one inside Egypt and two from surrounding areas. The six models are outperformed by the estimated Tm by a root-mean square error of 3.95 k. Therefore Egypt Tm new model’s performance is slightly improved compared to the latter models within RMS of 4.49 k. A final case to develop Tm, Tm model is dividing into groups according to the surface tem￾perature (TS) to improved RMS up to 3.1 K. Last but not least the developed Tm model will be of certain practical value in high-precision Precipitable Water Vapor (PWV) calculation in Egypt.