Temperature has an impact on the rate of photosynthesis. The rate of photosynthesis increases as the temperature rises, meaning it increases on hot days. The loss of water through the stomata is known as transipiration. If the temperature is too hot, the stomata closes off to prevent water loss. When the stomata closes off, this leads to a reduced C02 intake, then leading to a reduction and finally stoppage of photosynthesis as C02 is needed for photosynthesis.