The radar antenna intercepts thermal radiation from various external sources. Noise varies over time and at different elevation and azimuth positions of the antenna. The traditional weather radar noise power estimation methods cannot explain the variations of noise power in azimuth. First, this paper introduces the research status of weather radar noise power estimation. Second, the RadialBased Noise power Estimation algorithm (RBNE) is described, and the steps of the RBNE algorithm are described in detail by simulation. Finally, the performance of the RBNE algorithm is tested by the measured data of the Sband weather radar. The results show that the algorithm can relatively accurately estimate the noise power at each antenna location in real time, which helps to eliminate certain types of radial interference and helps to improve the weather radar data quality.