To study the effects of urban lake wetlands with different areas (WA), geometry (landscape shape index, LSI), and location with reference to a defined city center (DIST), and surrounding a non-built-up area proportion around 500 m of wetland (PB) on air temperature and relative humidity in summer, fourteen urban lake wetlands in central areas of Wuhan were selected. The temperature and relative humidity in summer were measured using small-scale quantitative measurement methods. Furthermore, the relationships between air temperature, relative humidity of urban lake wetlands, and WA, LSI, DIST, and PB were investigated to provide a scientific background for the construction of urban lake wetlands. The results showed that (1) the air temperature was negatively correlated with WA and DIST (P < 0.05), and positively correlated with LSI. The air relative humidity was positively correlated with WA, DIST, and PB, and negatively correlated with LSI(P < 0.05).The area of the lake wetland had the greatest effect on variations in temperature and relative humidity.(2)The benefits of urban lake wetland on temperature and relative humidity were associated with the areas of fourteen lake wetlands. Furthermore, the order was lake wetlands 11-14> lakes 6-10> lakes 1-5. The urban lake wetlands that had an area of 9.2-12.2 ha had an obvious effect on the decrease in temperature and increase in humidity. When the area of wetland was around 308.4 ha, its effect on the decrease of temperature was stable; and for the increase in humidity, the area was around 67.6 ha (P < 0.05). When the urban lake wetland area reached a certain critical value, it would have an obvious effect on the decrease in air temperature and increase in humidity with dispersive lake wetlands in the urban environment.