To better understand the cooling effect of a raingarden in Fitzroy Gardens, Melbourne, as well as its benefits for an urban microclimate, two rounds of 36-h microclimate monitoring at the raingarden were conducted. Land surface temperature and soil moisture were analyzed according to monitoring data. The results show a clear raingarden cooling effect in summer. The largest difference of land surface temperatures inside and outside the raingarden can reach 23.6 ℃, and the diurnal variation in temperature inside the raingarden was much less than that outside the raingarden. The soil moisture increased rapidly after irrigation, with the increase in the volumetric water content (VWC) of 2% to 3.6%. The soil moistures of adjacent irrigated garden beds and grass were higher than those inside the raingarden. Monitoring soil moisture helps guide raingarden irrigation.