Radios can be used as point sources of signal energy. Using this fact allows measurement of electromagnetic signal attenuation and delay due to a local environment. This project tests the idea of using small radios to measure changes in time of flight delay caused by air humidity.  By sending a simple message to a radio which echoes the message back, one can measure the time of flight. This will allow an indirect means of measuring water vapor in air. Our research measures delay using a frequency counter for precision. The echo server is twenty meters away from a base station where time of flight measurements occur. So far, results have been inconclusive due to lack of rain storms which are required to see large swings in air humidity. If shown to be practical, this would be a way to measure humidity over a large area with equipment costing less than $100."