The use of microwave links in wireless networks to monitor rainfall and water vapor is the latest technology in atmospheric environmental monitoring. This technology can measure meteorological elements such as rainfall and water vapor near the surface and has the advantages of high spatial and temporal resolution and low cost. The water vapor density from June 13, 2017 to July 13, 2017 is calculated and analyzed by using the data of the microwave communication link in the E-band of Gothenburg provided by Ericsson, the data of meteorological station 1 provided by the meteorological station at one end of the link and the data of meteorological station 2 provided by the meteorological website of the Swedish Institute of Meteorology and Hydrology （SMHI）. The results show that the environmental conditions at different locations in the same area have certain differences, the temperature of the same area shows a variation 0~4℃, the correlation between the two is 0.87; We retrieved water vapour density value from the microwave communication link and compared with the measurement from ground weather station in the study area, and we found the results have good consistency. The correlation between the two is 0.89, and the root mean square error is 0.75g/m3. We have demonstrated that microwave links can be utilized to provide an extra rich data source for existing weather monitoring networks in addition to existing humidity monitoring methods.