Perovskite appears to be the most promising candidate for thin-film solar cells due to its excellent optoelectronic properties, low-cost fabrication, and high photovoltaic performance. However, tin-based perovskite solar cells possess few issues related to thermal instability and poor performance. A study on thermal instability will be important to know the inner mechanism of the device. To find out the cause of thermal instability, a study on the temperature coefficient of different electrical and photovoltaic parameters is necessary. In this work, the effect of temperature on electrical and photovoltaic parameters of lead-free tin-based perovskite solar cells having ITO/ETL/CH 3 NH 3 SnI 3 /HTL architecture has been studied using a SCAPS-1D simulator. The coefficients of the temperature of these parameters have been calculated. Titanium dioxide has been used as the electron transport layer and Spiro-OMeTAD as the hole transport layer. The dark current–voltage analysis shows the positive temperature coefficient of barrier height and negative temperature coefficient of ideality factor. The estimated values of absolute temperature coefficient of barrier height and ideality factor are 170 μeV per K and 0.0017 per K, respectively. The light current–voltage (J-V) analysis shows negative temperature coefficients for all photovoltaic parameters. The absolute temperature coefficient of open-circuit voltage, short-circuit current, fill factor, and power conversion efficiency is 1.6 mV per K, 9 μA/cm 2 per K, 0.031 per K, and 0.074 per K, respectively. This study reveals the temperature sensitiveness of lead-free tin-based perovskite solar cells. The decrease in the value of different device parameters will be very informative for further study to get temperature invariant performances of lead-free perovskite solar cells.