Abstract: In order to analyze the characteristics of air, water, and soil temperatures and assess the effectiveness of water regulation for mitigating disasters, environmental temperatures were recorded using a cropland microclimatic and real observation system supplemented with manual observation. The results indicated that the accumulated water temperature was the highest and the accumulated air temperature was the lowest. Daily mean air temperature was lower than daily mean water and soil temperatures during the vegetative growth stage. The differences among air, water, and soil temperatures were quite small during the reproductive growth stage, they were all about 4℃ higher than the corresponding values during the vegetative growth stage. When leaf area index (LAI) was low or declining, water was illuminated directly by solar radiation. Consequently, water temperature was normally higher than air temperature at noon. Water temperature was higher for 9-10 hours. Water had large heat capacity and could be used to adjust the temperature. When heat-forced maturity occurred, irrigation of flowing water lasting for 3 days might cause daily maximum and mean air temperatures over the canopy to decrease 2.5℃and 1.0℃, respectively. Such treatment might result in the increases of crude fat and amylocellulose content of rice. Chalk degree of rice decreased. The irrigation might also cause the setting percentage to increase and the thousand-grain weight to increase by 6.65%. LAI was negatively correlated with water temperature. During heat-forced maturity period, LAI declined while water and soil temperatures were high. Water regulation was able to improve yield and quality of rice. Irrigation with flowing water for 2-3 days might obtain optimal achievements.