The effect of temperature and relative humidity on WE FM radio station (106.3MHz) Abuja, Nigeria, during Harmattan period was carried out with the measurement of frequency modulation (FM) signal strength by digital CATV signal meter and the temperature and relative humidity measured by digital Hygrometer/thermometer. It was observed that the signal strength was lower during the sunny period but higher in the morning and evening when there was little or no sun. It was also found out that both temperature and relative humidity have effect on the radio station signal strength with the correlation coefficient of -0.79 between signal strength and temperature, and 0.91 between signal strength and relative humidity.It was concluded from the correlation coeffici signal strength is directly proportional to the relative humidity but inversely proportional to the temperature, but the effect of both was higher in harmattan than in rainy season when compared to our the result of our previous work on the same station.