What Is the Air Quality in Fremont, Wyoming?

Fremont, Wyoming earns a C — air quality is fair, but not great. With a 5-year median AQI of 46, the city sees a meaningful number of "Moderate" days each year, when the EPA flags air as a concern for unusually sensitive people.

Fremont, Wyoming's 5-year median AQI of 46 is 5 points above the national average of 41 — meaningfully more polluted than the typical U.S. metro tracked here. Within Wyoming, Fremont, Wyoming runs more polluted than the state average of 37 — local sources or geography are concentrating pollution above the state's typical reading.

For context within Wyoming: Carbon, Wyoming currently holds the state's cleanest grade (A, AQI 16), while Johnson, Wyoming sits at the bottom (C, AQI 40).

Air quality in Fremont, Wyoming has held roughly steady over the past decade, with year-to-year shifts in median AQI of less than half a point. That stability makes the city's long-run grade a reliable signal of what residents can expect day-to-day.

In 2014, Fremont, Wyoming posted a median AQI of 45. By 2023 that figure was 49 — a rise of 4 AQI points dirtier across 10 years of EPA records.

Across the past five years, this area has logged just 18 days where AQI rose into the "Unhealthy for Sensitive Groups" range or worse — about 4 days per year, or roughly one every other month. That is a low count by national standards.

Healthy adults can continue normal outdoor activity in most weather, but should pay attention to AQI alerts during the worst pollution windows. People with asthma, heart disease, or pregnancy should reduce prolonged or intense outdoor exertion on flagged days, and consider running an indoor HEPA air cleaner during peak season. Because ozone peaks in the afternoon on hot sunny days, plan outdoor exercise for early morning or after sunset on bad-air days.