Abstract: Urban green space can improve the microclimate and alleviate urban heat island effect.From June 2013 to January 2014,according to“Surface meteorological observation Standard”,two surface meteorological observation stations with same instruments were set up inside and outside the forest in Tianjin Water Park for continuously determining the meteorological factors inside and outside the forest,and the forest’effects on city microclimate regulation was quantitatively researched.The results indicated that:1)Solar radiation peaked in August,outside nearly three times higher than in the forest.2)Precipitation reached maximum in July,in the forest,it only accounted for 67% of the outside.3)Wind speed in winter was higher than in summer,compared with the outside,forest could reduce 27%~73%,and the leading wind direction was south-west and north.4)Compared with outside the forest,in summer,the forest played a role in cooling and moisturizing;in autumn and winter,it played a role in raising temperature and lowering wetness.5)The change of soil temperature was consistent with the air temperature.The results can provide sound basis for forest improving urban microclimate.

Key words: urban forest, sun radiation, temperature, humidity and precipitation, wind speed