Air Quality Index (AQI) in Sierra Leone 🇸🇱

Live Air Quality Index (AQI) and PM2.5 Levels in Sierra Leone

Currently, the Air Quality Index (AQI) in Freetown, the capital of Sierra Leone, is measured at a score of 12. According to the US EPA health standard, this air quality rating is categorized as Good. The current atmosphere in Freetown is influenced by a PM2.5 (fine particulate matter) concentration of 2.1 µg/m³ and PM10 levels recorded at 3.2 µg/m³. Monitoring of gaseous pollutants shows Nitrogen Dioxide (NO2) at 0.4 µg/m³.

Beyond the primary urban hubs, atmospheric conditions and smog levels fluctuate across Sierra Leone based on industrial output, traffic density, and local weather patterns. Real-time pollution data and respiratory health alerts are also being actively monitored in cities like Bo, Kenema, Koidu and Makeni. Tracking these air quality metrics is essential for residents nationwide to manage outdoor exposure and maintain respiratory safety during periods of increased particulate concentration.

Air Quality Snapshot: Sierra Leone Right Now

Across 5 monitored cities in Sierra Leone, live air quality currently ranges from a low of 9 AQI in Bo (the cleanest air right now) to a high of 28 AQI in Koidu (the most polluted). By US EPA health band, the nationwide distribution stands at 5 Good. The average fine-particulate (PM2.5) concentration across these cities is 2.6 µg/m³ — approximately 0.5 times the World Health Organization (WHO) annual air quality guideline of 5 µg/m³.

Sierra Leone Air Quality: Major Cities Index

Freetown
1
Bo
1

Kenema
1
Koidu
1

Makeni
1

* Air Quality Index (AQI) data for Sierra Leone is calculated using the US EPA standard. Information is processed from multiple monitoring stations detecting PM2.5, PM10, and gaseous pollutants to ensure accuracy for respiratory health planning.

What Today's Readings Mean in Sierra Leone

The median reading across 5 monitored cities is 12 AQI. The national spread is 19 points, from 9 in Bo to 28 in Koidu. Average PM2.5 is 2.6 µg/m³ (0.5× the WHO annual guideline).

All monitored locations are currently in the Good range. Normal outdoor activity is appropriate for most people.

See the complete AQI and pollutant reference scales

Health & Scientific Resources

→ How to read US EPA Air Quality Index before going outside → Understanding Air Quality Index levels and what they mean → When haze forms and what it does to air quality

Air Quality in Sierra Leone — FAQ

Common questions about AQI levels, pollutants, and data sources for Sierra Leone.

What is the current air quality in Sierra Leone?

Live AQI readings for 5 city(ies) across Sierra Leone are listed above on the US EPA 0-500 scale.

Where does Sierra Leone's AQI data come from?

Real-time readings come from ground-based monitoring stations operated by national environmental agencies in Sierra Leone, delivered via WeatherAPI.com and aggregated using the EPA AQI formula.

What is a healthy AQI value in Sierra Leone?

On the EPA scale used worldwide, 0-50 is Good, 51-100 is Moderate, 101-150 is Unhealthy for sensitive groups, 151-200 is Unhealthy, 201-300 is Very Unhealthy, and 301-500 is Hazardous. The WHO 24-hour PM2.5 guideline is 15 μg/m³.

Why do AQI readings vary between cities in Sierra Leone?

Air quality is highly local — major pollution sources (traffic, industry, dust, wildfires) cluster around cities, while wind direction and topography move them around. Comparing nearby readings on this page is the best way to see how conditions change across Sierra Leone.