Answer:
Thanks for the question,
Due to the latitude and and distance from the equator the temperatures drop the further in a region,i.e. the equator because of the curvature of the world. In areas nearer to the poles, daylight has a larger space of atmosphere to experience and also the sun is at a lower angle within the sky.
In case of Canada and Mexico, Mexico lies near the equator and the sunlight directly hits the surface and therefore the climate and temperature in Mexico is constant and tropical. But, when we comes to Canada the latitudes increases and the temperature decreases due to the inconstant amount of sunlight. (Please check the attached Maps below which explains the latitude-temperature and latitude-climate effects)
Hope it helps!<3