Gravity is the force that an object receives from the earth, which is determined by the attraction of the earth and the centrifugal force due to its rotation. In the vicinity of the equator, the centrifugal force increases and it decreases slightly. On the other hand, when there are many high density substances in the ground, it increases. For example, in Okinawa, which has a latitude lower than that of Hokkaido, it becomes slightly lighter when measured with the same scale.
