What effect does weather have on the process of photosynthesis?

I think the answer is: Although the light dependent reactions of photosynthesis are not affected by changes in temperature, the light independent reactions of photosynthesis are dependent on temperature. They are reactions catalyzed by enzymes. As the enzymes approach their optimum temperatures the overall rate increases.

Photosythesis is affected by weather because during fall and the winter the chloraplasts in the cell start to die (loosing their green pigment). The chloraplast are the organelle that obtain the sunlight. When they stop obtaining the sunlight the process of photosynthesis stop along with it.