Coastal cities have very stable climates, this is due to the ocean influencing the air temperature. Due to the fact that water changes temperature much less readily than air, the oceans stabilize the temperatures all over earth. Even cities found far away from oceans are affected by the stable temperatures of the earth's water bodies.
Without the enormous amount of water in the earth's oceans, the temperature of cities on earth might be several hundred degrees F during the summer and far below zero degrees during the winter.
