The garbage smell
There are many reasons why it's hard to escape the stench, according to AccuWeather. New York City has the highest population density in the country. According to the U.S. Census, it's about 27,000 people per square mile, and that much body odor can cause problems. With that many people also comes a lot of garbage. When the heat and humidity get more intense in the summer, so does the smell. The city is usually warmer because of pollution, which causes a greenhouse effect and allows bacteria to grow faster and also contributes to the smell.
As the weather heats up, the thin layer of urine, garbage juice and pigeon poop that lightly coats our city’s streets begins to be gently cooked by the sun like a delicious skillet of huevos en purgatorio. As a result, the semen trees of spring soon curdle into a pervading scent more akin to a suburban waste treatment plant. Thank goodness, we spend most of our summers on roofs. And the garbage smell is really a gross thing you’ll experience in New York City as summer arrives.