If you're asking about HF and lower, electrical activity is higher in the summer months in the Northern hemisphere, and can introduce more background noise on a signal, making weaker signals (lower power or more distant) more difficult to pick out. Listening fatigue can be more pronounced due to this.
However, your receiving range won't be affected much, if at all due to the seasons.
Sunspots follow a roughly 11 year cycle, and you can hear more distant stations more easily during the peak of the cycle than you can at the lowest point of the cycle.
If you are asking about VHF and up, as mentioned above, foliage in the Spring and Summer months can absorb signals in the 400 MHz and 700/800/900 MHz bands, somewhat reducing the signal strength of those stations, and making the signal weaker, possibly reducing the range at which you can hear more distant stations.
John
Peoria, AZ