All communication frequencies throughout the spectrum are affected in varying degrees by:

The sun is the ultimate powerhouse and primary driver of almost all radio propagation phenomena on Earth. Its radiation creates the ionosphere, which dominates High Frequency (HF) long-distance communication. Furthermore, the sun's thermal energy drives the Earth's weather patterns and creates temperature inversions in the troposphere, which strongly influence VHF and UHF propagation. While the ionosphere, auroras, and meteor showers certainly affect specific bands and modes, only the sun has a varying degree of influence across all communication frequencies throughout the entire spectrum.