AIR QUALITY SD

Air Quality in Rapid City, SD: Good (37 AQI)

AQI 37 · Good · Ozone · Updated 2026-05-03

Rapid City's air quality is good. Air pollution poses little or no risk.

Data: EPA AirNow, FEMA National Risk Index Last verified: 2026-05-03

Average AQI

Good

AQI Category

Wildfire Risk

Mold Score

ZIP Codes

What is AQI?

The Air Quality Index (AQI) is a standardized scale from 0 to 500 that measures air pollution levels. 0-50 is "Good," 51-100 is "Moderate," 101-150 is "Unhealthy for Sensitive Groups," and above 150 is "Unhealthy" for everyone. AQI tracks five major pollutants: ground-level ozone, particulate matter (PM2.5 and PM10), carbon monoxide, sulfur dioxide, and nitrogen dioxide. Rapid City's average AQI of 37 falls in the "Good" range.

How do wildfires affect air quality?

Wildfire smoke contains fine particulate matter (PM2.5) that can travel hundreds of miles and dramatically spike AQI readings. During fire season, even cities far from active fires can experience unhealthy air. HEPA air purifiers (rated for PM2.5) are the most effective indoor protection. Check AirNow.gov for real-time conditions during fire season.

Air Quality by ZIP Code in Rapid City

AQI varies across Rapid City's 4 ZIP codes based on proximity to pollution sources and local geography.

ZIP Code	AQI	Category	Wildfire	Mold
57701	37	Good	43	41	View report →
57702	37	Good	43	41	View report →
57703	37	Good	43	29	View report →
57709	37	Good	43	21	View report →

Air Quality Overview

Rapid City, South Dakota has good air quality with an average AQI of 37. This means air pollution poses little or no risk. The dominant pollutant measured is Ozone.

The Air Quality Index (AQI) is an EPA-standardized scale from 0 to 500. Values below 50 are "Good," 51-100 "Moderate," 101-150 "Unhealthy for Sensitive Groups," 151-200 "Unhealthy," 201-300 "Very Unhealthy," and above 300 "Hazardous."

Dominant Pollutant: Ozone

Ground-level ozone forms when pollutants from cars, power plants, and industrial facilities react with sunlight. Unlike stratospheric ozone, ground-level ozone is harmful to breathe.

Health effects of ozone exposure:

Irritation of the respiratory system
Reduced lung function
Aggravation of asthma and chronic lung diseases
Increased susceptibility to respiratory infections

Peak times: Ozone levels are typically highest on hot, sunny afternoons. Exercise outdoors in the morning when levels are lower.

Air Quality by ZIP Code in Rapid City

AQI varies across Rapid City's 4 ZIP codes based on proximity to pollution sources, traffic patterns, and local geography:

ZIP Code	AQI	Category	Wildfire Risk	Mold Score
57701	37	Good	43	41
57702	37	Good	43	41
57703	37	Good	43	29
57709	37	Good	43	21

Wildfire Smoke Risk

Rapid City has an elevated wildfire smoke risk with an average smoke risk score of 43 (scale 0-100). There have been 130 fires recorded within 100 km of city ZIP codes.

Metric	Value
Avg. smoke risk score	43
Max smoke risk score	43
Fires within 100 km	130
High-risk ZIP codes	0

Wildfire smoke contains PM2.5, carbon monoxide, and volatile organic compounds. Even short-term exposure can trigger asthma attacks and respiratory distress.

Indoor Mold Risk

Rapid City has an average mold risk score of 33 out of 100.

Factor	Value
Mold risk score	33/100
Average humidity	62% RH
High-risk ZIPs	0
Peak season	balanced

Mold risk is influenced by humidity levels, housing age (older homes have more moisture issues), flood history, and water infrastructure quality. Indoor humidity above 60% creates favorable conditions for mold growth.

Signs of mold problems: musty odors, visible growth on walls or ceilings, worsening allergies indoors, condensation on windows. Professional mold testing ($300-$600) can identify hidden issues.

Health Recommendations

With good air quality (AQI 37), Rapid City residents can enjoy outdoor activities without significant restrictions. General tips:

Monitor AQI during wildfire season for temporary spikes
Use HEPA air purifiers indoors if you have respiratory conditions
Maintain indoor humidity between 30-50% to prevent mold

Rapid City vs. Nearby South Dakota Cities

How Rapid City's air quality compares to nearby cities:

City	AQI	Category	Population
Rapid City	37	Good	86,567
Aberdeen	54	Moderate	50,402
Columbia	54	Moderate	27,989
Watertown	60	Moderate	27,242

ZIP Codes in Rapid City

Rapid City covers 4 ZIP codes. Air quality can vary by neighborhood based on proximity to highways, industrial areas, and green spaces. Check your specific ZIP code for localized data.

Data Sources

Air quality: EPA AirNow — real-time and historical AQI data
Wildfire risk: FEMA National Risk Index
Mold risk: Derived from EPA, FEMA, Census ACS (humidity, housing age, flood history)
Monthly AQI: EPA Air Quality Statistics

Updated daily.

Frequently Asked Questions

Is the air safe to breathe in Rapid City?

Yes — Rapid City's average AQI is 37 (Good). Air pollution poses little or no risk for the general population.

How many unhealthy air days does Rapid City have?

Rapid City has zero recorded unhealthy air quality days, which is excellent. Air quality can still vary seasonally due to wildfire smoke, pollen, or industrial activity.

What is the AQI in Rapid City?

The average Air Quality Index (AQI) in Rapid City is 37, categorized as Good. The primary pollutant is Ozone. AQI ranges from 0-500, where 0-50 is Good, 51-100 Moderate, 101-150 Unhealthy for Sensitive Groups, and 151+ Unhealthy.

What is the wildfire risk in Rapid City?

Rapid City has a wildfire risk score of 43 out of 100. Moderate wildfire risk means smoke events are possible. Having a HEPA air purifier available is recommended.

Is mold a concern in Rapid City?

Rapid City has a mold risk score of 33 out of 100, based on humidity, precipitation, and temperature data. Maintain good ventilation and address any water intrusion promptly to prevent mold growth.

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