Houston is the Smelliest City in the USA, Says Survey

687 Industrial Facilities and Brutal Humidity

Houston has a new title, and it is not a good one. A 2025 study by Prilla analyzed 74 major U.S. cities for odor-related factors and named the Texas metropolis the smelliest in America.

The ranking looked at everything from sewage complaints and landfill density to industrial facilities and air quality.

Houston scored a “freshness score” of just 56.09 out of 100, dragged down by nearly 700 industrial sites, 63 unhealthy air days in 2024, and summer humidity that makes everything stick.

The city sits along a 52-mile stretch of petrochemical plants that pump pollution into neighborhoods where some residents live 20 years shorter than people in wealthier areas nearby.

How Researchers Measured the Stink

The study examined sewage complaints, landfill density, unhealthy air days, industrial facilities, pet ownership, and even Google searches for “why does my city smell” to calculate a City Freshness Score.

Houston had 687 industrial facilities and 63 unhealthy air quality days in 2024. The city also logged almost 50 sewage complaints per 100,000 residents.

Combine those numbers with Texas heat and you get a city where odors do not just appear, they settle in and stay.

Nearly 700 Industrial Sites in One Metro

Houston’s low freshness score was driven by nearly 700 industrial facilities within city limits.

These include refineries, chemical plants, plastics manufacturers, and waste processing operations scattered across the metro area.

The top industrial polluters in Harris County are overwhelmingly petrochemical companies, responsible for millions of pounds of chemical releases.

Three facilities alone account for more than half of chemical air pollution from industrial sources around Houston.

The 52-Mile Chemical Corridor

The Houston Ship Channel stretches 50 miles from downtown Houston to the Gulf of Mexico. The channel is home to roughly 600 petrochemical facilities.

The Ship Channel area has one of the highest densities of petrochemical facilities in the world. These plants process oil and gas into plastics, fuels, and chemicals around the clock.

Industrial activity is constant and chemical odors regularly pervade homes and schools in nearby neighborhoods.

Humidity Traps the Smell

Houston’s subtropical climate produces hot, humid conditions during summer months. The average humidity in Houston is 75% throughout the year.

The humidity level is usually very high in summer, at around 80%. When temperatures hit the mid-90s, that moisture makes odors cling to everything.

The summer heat and humidity exacerbate matters, and 37% of Houstonians said traffic congestion was a top issue, contributing to poor air quality and the smell of gas in the air.

63 Unhealthy Air Days Last Year

Houston led the state in the number of ozone action days in 2024 with 49, where excessive ozone is unhealthy for certain people.

The 2025 “State of the Air” report found that the Houston metro area ranked 7th worst in the nation for ozone pollution.

On June 20, 2024, EPA reclassified the six-county Houston-Galveston-Brazoria area from moderate to serious nonattainment for ozone standards.

The city has been missing federal air quality targets since the 1990s.

Sewage and Landfills Add Layers

New York had significantly more sewage complaints than Houston, 79. 62 per 100,000 residents versus 49.73, but other odor factors weighed Houston down.

From 2015 to 2018, residents near Blue Ridge Landfill filed over 4,500 complaints to state regulators over the smell.

As Houston heads toward producing 5.4 million tons of waste annually by 2040, the space available at its five landfills will decrease by a third within the next 15 years.

Fenceline Communities Pay the Price

People in communities near the ship channel, predominantly low-income communities of color, have life expectancies up to 20 years shorter than largely white and affluent areas about 15 miles away.

Air pollution in the Houston region is disproportionately experienced by people of color, people living in poverty, and limited-English households.

There have been 15 chemical explosions, fires and toxic releases reported along the Houston Ship Channel since 2021.

LA and New York Round Out Top Three

Los Angeles ranked second with 134 unhealthy air days and more than 62 sewage complaints per 100,000 people.

New York came in third despite fewer industrial facilities than Houston or LA, racking up nearly 80 sewage complaints per 100,000 people, the highest among the top three.

Orlando, Anaheim, Riverside, Long Beach, Phoenix, Portland, and Chicago filled out the rest of the top ten.

Reno Smells Like Sagebrush

Reno takes the crown as the freshest-smelling city in the U.S. with a score of 90. 2.

Low sewage complaints, minimal industrial activity, and only four unhealthy air days make it stand out.

Desert climates and lower humidity help keep bad smells from lingering, which is one reason mountain and coastal cities in the West dominated the fresh air rankings. Honolulu came in second and Anchorage third.

The EPA Deadline Houston Keeps Missing

The greater Houston area has been missing the mark on shifting ozone limits since the 1990s, never reducing its concentrations to a level deemed healthy.

The new deadline for attaining the ozone standard is August 3, 2027, for the Houston-Galveston-Brazoria area.

Texas must revise the state clean-air plan to include more stringent measures for emissions control and contingency planning. If the area fails again, penalty fees kick in for major polluters.

A City That Runs on What Makes It Smell

Houston’s economy depends on the same industries fouling its air. Plastics producers in Texas sold $61.5 billion in materials and employed 54,000 people in 2023, more than any other state.

The Port of Houston drives $906 billion in annual national economic value and sustains more than three million U.S. jobs.

The smell is not going anywhere soon, but neither are the paychecks. For now, Houston wears its new title whether it wants to or not.

This article was created with AI assistance and human editing.

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