ATHENS — The peak tourist season is beginning in Athens, but visitors to the ancient city on Thursday were confronted with a monument to modern-day Greece: the mountains of garbage festering on the streets of the capital, where a strike by state sanitation workers over job security entered its 13th day amid an oppressive heat wave.

This is not the first time that Greeks have been forced to circumnavigate piles of trash on sidewalks because of a protracted strike. But the unseasonably high temperatures, which topped 100 degrees Fahrenheit on Thursday and are expected to climb higher over the weekend, have created an exceptionally stifling and fragrant atmosphere for Athenians and for tourists.