Fine particles
10.4µg/m³CAMS model • Open-Meteo
Sierra LeoneAir quality, PM2.5 and PM10
Compare air quality across cities in this country. Explore PM2.5, PM10 and other pollutant concentrations, check data timestamps, and view recent trends and historical charts.
Sierra Leone - average concentrations across available points: PM2.5: 10.4 µg/m³, PM10: 12.8 µg/m³, O₃: 26.4 µg/m³, NO₂: 6.1 µg/m³, SO₂: 1.1 µg/m³, CO: 181.6 µg/m³. Date range: September 26, 2026. Each point contributes its latest available hourly value; this is not a daily or population-weighted average.
Lowest PM2.5: Kenema (5.8 µg/m³). Highest PM2.5: Kindia (13.3 µg/m³). This comparison covers 5 cities on September 26, 2026 using their latest available hourly values. Reading times may differ; this is not an annual-average ranking.
Air quality questions →All cities · Sierra Leone
5 citiesSierra Leone↗
Camayenne
PM2.511.6
PM1016.7
µg/m³
PM2.5 · FairNO₂ 3.7O₃ 35
September 26, 202601:00
Sierra Leone↗
Freetown
PM2.511.6
PM1015.6
µg/m³
PM2.5 · FairNO₂ 4.3O₃ 32
September 26, 202601:00
Sierra Leone↗
Bo
PM2.59.7
PM1010.9
µg/m³
PM2.5 · FairNO₂ 8O₃ 28
September 26, 202601:00
Sierra Leone↗
Kenema
PM2.55.8
PM106.6
µg/m³
PM2.5 · FairNO₂ 5.6O₃ 25
September 26, 202601:00
Sierra Leone↗
Kindia
PM2.513.3
PM1014.2
µg/m³
PM2.5 · FairNO₂ 8.7O₃ 12
September 26, 202601:00
PM2.5 vs PM10 - what is the difference? → · Models and monitoring stations →
AVERAGE ACROSS AVAILABLE COUNTRY POINTS
Latest concentrations · Sierra Leone
Particulate matter
12.8µg/m³Ozone
26.4µg/m³Nitrogen dioxide
6.1µg/m³Sulphur dioxide
1.1µg/m³Carbon monoxide
181.6µg/m³Average of the latest available hour at each model point. This is neither a population-weighted nor a daily average.
DAILY DATA · Sierra Leone
Sierra Leone - air pollution over recent days (2026-08-31 - 2026-09-25)
Averages across available points in the country. These are not population-weighted averages.
PM2.5Lowest 3.27 2026-09-23Highest 8.6 2026-09-252026-08-31 - 2026-09-25
PM10Lowest 4.6 2026-09-23Highest 11.76 2026-09-252026-08-31 - 2026-09-25
O₃Lowest 34.53 2026-09-24Highest 47.37 2026-09-072026-08-31 - 2026-09-25
NO₂Lowest 1.35 2026-09-23Highest 3.62 2026-08-312026-08-31 - 2026-09-25
SO₂Lowest 0.33 2026-09-23Highest 0.9 2026-08-312026-08-31 - 2026-09-25
COLowest 133.07 2026-09-23Highest 192.87 2026-09-032026-08-31 - 2026-09-25
Scroll the chart or table sideways to see the full period.
| Pollutant | 2026-09-25 | 2026-09-24 | 2026-09-23 | 2026-09-22 | 2026-09-21 | 2026-09-20 | 2026-09-19 | 2026-09-07 | 2026-09-06 | 2026-09-05 | 2026-09-04 | 2026-09-03 | 2026-09-02 | 2026-09-01 | 2026-08-31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 | 8.6 | 6.29 | 3.27 | 4 | 5.51 | 6.62 | 4.54 | 5.58 | 7.72 | 6.03 | 3.94 | 5.14 | 4.2 | 6.24 | 6.5 |
| PM10 | 11.76 | 9.04 | 4.6 | 6.02 | 7.43 | 9.93 | 6.55 | 10.29 | 11.72 | 8.03 | 6.23 | 7.46 | 5.88 | 9.88 | 7.49 |
| O₃ | 37.47 | 34.53 | 36.72 | 38.95 | 37.72 | 40.52 | 41.56 | 47.37 | 41.02 | 42.86 | 45.6 | 44.53 | 41.81 | 40.98 | 40.17 |
| NO₂ | 2.97 | 1.8 | 1.35 | 2.06 | 2.41 | 1.74 | 1.44 | 2.07 | 2.45 | 2.76 | 1.91 | 2.27 | 2.03 | 2.01 | 3.62 |
| SO₂ | 0.67 | 0.48 | 0.33 | 0.47 | 0.66 | 0.5 | 0.38 | 0.71 | 0.72 | 0.68 | 0.59 | 0.57 | 0.55 | 0.65 | 0.9 |
| CO | 156.98 | 140.29 | 133.07 | 148.86 | 150.3 | 147.58 | 154.81 | 174.1 | 162.92 | 177.65 | 180.96 | 192.87 | 177.64 | 169.29 | 180.26 |
A dot on the chart and a dash in the table indicate missing data. The latest day may be incomplete.
WEATHER & SURROUNDINGS
Sierra Leone · weather forecast
Daily maximum and minimum temperatures. Forecast point: 8.5, -11.5.
Scroll the forecast to see the following days.
Sierra Leone · September 23, 2026: minimum temperature 20.7°C, maximum 22.1°C. Wind: 8.9 km/h. Humidity: 99%.
Full forecast: temperature, rainfall, wind and humidity
| Date | Day °C | Min °C | Max °C | Night °C | Rain mm | Wind m/s | Humidity % | Clouds % |
|---|---|---|---|---|---|---|---|---|
| 2026-09-23 | 21.5 | 20.7 | 22.1 | 20.7 | 56.8 | 2.5 | 99 | 100 |
| 2026-09-24 | 28.4 | 20.3 | 29.1 | 20.3 | 3.5 | 2.7 | 57 | 99 |
| 2026-09-25 | 29.2 | 19.1 | 31.5 | 21.9 | 0.1 | 2 | 56 | 95 |
| 2026-09-26 | 26.2 | 20.4 | 27.8 | 21.6 | 3.7 | 1.3 | 70 | 95 |
| 2026-09-27 | 28.3 | 21.2 | 29.6 | 21.7 | 8.7 | 1.6 | 65 | 100 |
| 2026-09-28 | 25.2 | 20.4 | 25.6 | 21.5 | 10.9 | 1.5 | 91 | 82 |
| 2026-09-29 | 26 | 21.2 | 26 | 22.1 | 10.1 | 1.2 | 81 | 100 |
| 2026-09-30 | 30.1 | 21.6 | 30.6 | 22.6 | 4.1 | 1.4 | 59 | 99 |
| 2026-10-01 | 30.7 | 21.8 | 30.7 | 22.1 | 19.8 | 1.8 | 58 | 85 |
| 2026-10-02 | 30.4 | 20.8 | 30.4 | 22 | 17.5 | 2.2 | 58 | 98 |
| 2026-10-03 | 26.5 | 21.5 | 26.5 | 21.9 | 26 | 1.7 | 80 | 98 |
| 2026-10-04 | 26.4 | 20.9 | 26.4 | 21.5 | 30.1 | 1.1 | 76 | 100 |
| 2026-10-05 | 26.3 | 20.3 | 26.3 | 20.8 | 7.1 | 1.1 | 86 | 100 |
| 2026-10-06 | 25.4 | 20.8 | 25.4 | 22.1 | 9.4 | 1.3 | 89 | 100 |
| 2026-10-07 | 28.4 | 20.4 | 28.4 | 22 | 6.8 | 2 | 67 | 100 |
| 2026-10-08 | 24.5 | 21.5 | 29.5 | 22.1 | 3.1 | 1.4 | 89 | 100 |
| 2026-10-09 | 29.7 | 21.3 | 29.7 | 21.7 | 12.1 | 1.1 | 62 | 100 |
| 2026-10-10 | 29.8 | 21.3 | 29.8 | 24.2 | 9.2 | 1.5 | 61 | 90 |
UV index by day · Sierra Leone
Data for a country reference point. Local conditions may differ.
SPF 50, long sleeves and shade between 10:00-16:00.
0-2 low3-5 moderate6-7 high8-10 very high11+ extreme
Scroll the forecast to see the following days.
Sierra Leone · September 25, 2026: UV index: 8.3 .
| Indicator | 2026-09-25 | 2026-09-26 | 2026-09-27 | 2026-09-28 | 2026-09-29 | 2026-09-30 | 2026-10-01 | 2026-10-02 | 2026-10-03 | 2026-10-04 | 2026-10-05 | 2026-10-06 | 2026-10-07 | 2026-10-08 | 2026-10-09 | 2026-10-10 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index | 8.3 | 5.7 | 7.9 | 7.6 | 8 | 7.6 | 8.8 | 6.3 | 8 | 3.3 | 4.3 | 4.5 | 5.2 | 5.6 | 7.5 | — |
AIR QUALITY QUESTIONS
Sierra Leone · air pollution - questions and answers
What do the latest air quality data show for Sierra Leone?
Sierra Leone - average concentrations across available points: PM2.5: 10.4 µg/m³, PM10: 12.8 µg/m³, O₃: 26.4 µg/m³, NO₂: 6.1 µg/m³, SO₂: 1.1 µg/m³, CO: 181.6 µg/m³. Date range: September 26, 2026. Each point contributes its latest available hourly value; this is not a daily or population-weighted average.
When was PM2.5 highest in Sierra Leone over the past week?
The highest available daily mean PM2.5 was 8.6 µg/m³ (September 25, 2026). This comparison covers 7 days with data in the seven days before September 26, 2026. The day of the latest reading is excluded because it may be incomplete.
Which cities in Sierra Leone have the cleanest and most polluted air by PM2.5?
Lowest PM2.5: Kenema (5.8 µg/m³). Highest PM2.5: Kindia (13.3 µg/m³). This comparison covers 5 cities on September 26, 2026 using their latest available hourly values. Reading times may differ; this is not an annual-average ranking.
Is the PM2.5 concentration for Sierra Leone an AQI score?
No. PM2.5 and PM10 are concentrations in µg/m³. AQI is a separate index calculated using a defined scale. When comparing air quality, also check other pollutants, the date and the averaging period.
What UV index does the available forecast show for Sierra Leone?
For September 25, 2026, the forecast UV index is 8.3. The UV section also shows the following available days.
What wind speed is forecast for Sierra Leone?
For September 23, 2026, forecast wind speed is 8.9 km/h. The weather table includes wind, temperature and other available parameters for subsequent days.
PM2.5 · PM10 · NO₂ · O₃
Understanding air quality and pollution data
What do PM2.5 and PM10 mean?
PM2.5 and PM10 are fractions of airborne particulate matter. PM2.5 covers fine particles up to 2.5 micrometres in diameter, while PM10 covers particles up to 10 micrometres. Concentrations in µg/m³ tell you how many micrograms of particles are present in a cubic metre of air. Compare values over the same time period.
Where does the air pollution data come from?
The latest concentrations come from the CAMS atmospheric model via Open-Meteo for each city’s coordinates. Values describe a model area, so conditions on individual streets may differ. Historical monitoring station data is shown separately where available.
How does PM2.5 concentration differ from AQI?
PM2.5 is the concentration of one particle fraction, expressed in µg/m³. AQI is an index calculated using a particular scale and thresholds. The pollutant cards show concentrations. Our city ranking compares PM2.5; PM10, ozone, nitrogen dioxide and other available gases add to the picture of air quality.
Which dates do the values and charts cover?
Each current value has a data date and time. Current concentration cards show the latest available hour, daily charts summarise individual days, and monthly records let you compare longer periods. These values represent different time intervals.
How can I check pollution in my city?
Search for your city and open its air quality page. Start with PM2.5 and PM10, then check the other available pollutants and the data timestamp. Charts and tables help you compare concentrations over time. Weather and historical climate information complement the pollution data.