Semiconductor silicon diodes are used widely as detectors in oncology radiation centers for In Vivo Dosimetry (IVD). IVD is the ultimate method used in cancer treatment centers to detect possible errors in dose delivery. Diode dosimetry is based on the linearity of diode current with dose. Number of carriers taking part in diode current, is proportional to dose received for practical dose range. However, carrier lifetime and mobility are temperature dependent. In addition dark current increases with temperature. Correction factors are therefore needed in order to offset dark current influence, whenever dose is measured at a temperature different from calibration or reference temperature. We investigate the effect on signal for three PTW diodes in a 18 MV photon beam generated by Elekta Synergy Accelerator and find correction factors for clinical range of temperatures.