With the rapid development of ultra-high voltage (UHV) power grids

electromagnetic environmental issues caused by radio interference (RI) from transmission lines have become increasingly prominent. Therefore

two-year monitoring data from the long-term observation station of the 750 kV transmission line in Guanting were utilized to conduct outlier processing of RI

andinfluencing factors under different weather conditions were analyzed. The results demonstrate that: (1) The proposed PSO-DELM method can be adopted to effectively detect RI outliers and achieve effective imputation of missing values

and the K-S test p value of the filled value is 0.398 4; (2) Under fair weather

RI exhibits a positive correlation with the ambient temperature

while atmospheric pressure exerts a significant inhibitory effect on RI; (3) The L50 value of the RI within one day in rainy days varies from 51.5 dB to 66.0 dB in this region

and rainfall intensity and relative humidity dominate RI during rainy conditions

both showing positive correlations

and RI stabilizes after a fluctuation adjustment phase post-rainfall; (4) The L50 value of the RI within one day in snowy weather varies from 56.5 dB to 65.5 dB in this region

and snowfall intensity strongly correlates with RI during snowy weather

followed by a prolonged adjustment period post-snowfall. This research provides a scientific basis for controlling RI in UHV transmission lines.