This paper presents hourly Global Horizontal Irradiance (GHI) measured data at three stations (Lahore, Multan, Bahawalpur) in Punjab, Pakistan. The estimated GHI data from three reanalysis datasets have also been presented. Clearness index (KT), Solar zenith angle (θsza) and Periodicity factor (Pf) were calculated and used to develop bias correction models. The estimated corrected GHI data using best model M20 for years 2015 and 2016 is also presented.