When visiting a new city, one of the first things you notice is how clean or dirty it feels. Streets full of litter, dirty air, and the sight of rats or cockroaches can leave a bad impression. Many big cities are often seen as messy and overcrowded, but that’s not always true.
A 2025 study by Oxi Fresh looked closely at how clean the biggest cities in the U.S. really are—and some surprising results came out. It turns out, even large cities can be neat, green, and pleasant to live in. Among the 35 biggest metro areas in the country, Portland, Oregon, and Seattle, Washington, stood out as the cleanest.
Portland, Oregon – America’s Cleanest City
Portland grabbed the number one spot in the study, earning an A+ grade for cleanliness. The city stood out in several areas like low cockroach and rodent presence, good air quality, and clean tap water. Only 1% of Portland homes reported cockroaches, compared to a shocking 20% in New York City.
One major reason behind Portland’s cleanliness is its low population density. With just 375 people per square mile, it’s far less crowded than cities like Los Angeles or New York. Less crowding means less litter and waste in public areas, making it easier for the city to stay clean.
Portland is also known for its beautiful natural surroundings. It has many green spaces, forests, and is located near the Willamette River. Around 30% of the city is covered by tree canopy, and these trees help clean the air by absorbing pollution.
The city also follows strong environmental rules. Back in 2008, Oregon’s Department of Environmental Quality started a program that reduced car travel by 50 million miles every year. This led to a cut of around 10,000 pounds of air pollutants. Portland also runs a program called Downtown Portland Clean & Safe, which hires teams to remove litter and graffiti from public places regularly.
Seattle, Washington – A Close Second
Seattle came in second in the cleanliness rankings, with an A grade. While its population density is nearly double that of Portland, it still manages to maintain high cleanliness standards. This shows that even busy, crowded cities can stay clean if proper systems are in place.
Seattle is known as one of the most outdoor-friendly cities in the U.S., and that’s partly because it has clean air and fresh water. According to the study, Seattle had 205 days of “good” air quality last year, which is excellent for a big city. In comparison, Los Angeles had only 37 good air quality days.
Rodent problems are also lower in Seattle. Only 5% of households reported rodent presence, compared to 9% in Portland and much higher numbers in other large cities.
Geography also plays a role. Seattle is surrounded by the Cascade Mountains and Puget Sound, both of which help provide clean water and fresh air. Ocean breezes from the sound help blow away polluted air and keep things fresh.
In 2019, the city launched the Seattle Green New Deal, focusing on cutting down pollution and protecting the environment, especially in low-income areas. It also runs a dedicated program called Seattle Clean City, aimed at keeping the streets tidy and safe for everyone.
The Importance of Clean Cities
A city’s cleanliness doesn’t just affect how it looks—it also affects health, tourism, and how happy people feel living there. While cities like New York and Los Angeles struggle with overcrowding, pollution, and pests, places like Portland and Seattle prove that urban living doesn’t have to mean dirty surroundings.
With smart planning, strong environmental policies, and community support, cities can be both vibrant and clean.
In the end, whether you’re planning to move or just take a trip, cleanliness can make a big difference. Portland and Seattle show that big cities can still feel fresh, safe, and welcoming.
FAQs
Q: Which is the cleanest city in America in 2025?
A: According to a 2025 study by Oxi Fresh, Portland, Oregon, is the cleanest city in America, earning an A+ grade for factors like air quality, low pest levels, and clean tap water.
Q: Why is Portland considered so clean?
A: Portland has a low population density, strong environmental policies, lots of green spaces, and effective public programs that keep the city clean and pollution-free.
Q: How did Seattle perform in the cleanliness ranking?
A: Seattle ranked second in the study with an A grade. It has good air and water quality, low rodent problems, and solid environmental initiatives like the Green New Deal.
Q: What were the dirtiest cities in the study?
A: Los Angeles ranked 34th and New York City was the dirtiest at 35th. Both cities had high rates of pests and fewer days of good air quality.
Q: Does low population density always mean a cleaner city?
A: Not always, but it helps. Portland’s low density supports better waste management. However, Seattle proves that even a high-density city can stay clean with the right systems in place.
