In 2011, an observational experiment was conducted on a large water body in Zhejiang Province with automatic observing stations deployed both upwind and downwind at the specified distances to observe temperature synchronously to study the quantitative regularities of the influence of water body on temperature. The results show that a water body has cooling effect in daytime and warming effect in nighttime on surrounding land, the closer the land to the water, the more significant the effect is; the warming effect in nighttime is more significant than the cooling effect in daytime, and the cooling effect in daytime is more significant from March to May than that from January to February; in a day, the cooling effect reaches its maximum at noon; a water area of 2 km2 has an obvious effect on the temperature observation within 100 m downwind, and much less obvious beyond 100 m. The study made a good attempt to quantify the scope and magnitude of the influence of water body on temperature measurements and provides a basis for the scientific location selection of meteorological stations.