Air quality
Air quality in Saint-Louis today
Updated
Unhealthy (US AQI 154) Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed. Model estimate for Sun, Oct 25, 8:00 pm (20:00 UTC).
Live AQI, PM2.5, PM10 and ozone for Saint-Louis, Senegal, with a 48-hour forecast and the best time to be outside.
- US AQI now
- 154 Unhealthy
- PM2.5
- 73 µg/m³ 4.9× WHO 24-h guideline
- PM10
- 166 µg/m³
- Ozone
- 47 µg/m³
- Dominant pollutant
- PM2.5 sub-index 154
- Best hour tomorrow
- 9:00 pm AQI 151
- European AQI
- 72
Air quality in Saint-Louis right now
Right now the modelled US Air Quality Index for Saint-Louis, Senegal is 154, which falls in the "Unhealthy" band (up to 200). Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed.
The index is driven mainly by PM2.5, whose own sub-index is 154. Fine and coarse particles come from traffic, heating, industry, dust and smoke; they build up on calm nights and clear when wind or rain arrives.
PM2.5 is 73 µg/m³, 4.9 times the WHO 24-hour guideline of 15 µg/m³; PM10 is 166 µg/m³ against a guideline of 45; ozone is 47 µg/m³ (below the WHO 8-hour level of 100); nitrogen dioxide is 1.7 µg/m³ (below the 24-hour guideline of 25).
Also this hour: desert dust at 170 µg/m³, high enough to haze the sky, carbon monoxide 105 µg/m³.
Saint-Louis AQI forecast: next 48 hours
Over the next 24 hours the AQI is forecast to range from 152 around Mon 8:00 pm to 159 around Mon 5:00 am, staying "Unhealthy" throughout.
The following day is expected to be cleaner, averaging about 109 against 157 for the next 24 hours.
| Local time (Africa/Dakar) | US AQI | Category | PM2.5 µg/m³ | PM10 µg/m³ | Ozone µg/m³ |
|---|---|---|---|---|---|
| Sun 8:00 pm | 154 | Unhealthy | 72.9 | 166 | 47 |
| Sun 11:00 pm | 156 | Unhealthy | 70.3 | 158 | 48 |
| Mon 2:00 am | 158 | Unhealthy | 65.9 | 151 | 48 |
| Mon 5:00 am | 159 | Unhealthy | 61.7 | 140 | 45 |
| Mon 8:00 am | 159 | Unhealthy | 62.2 | 138 | 45 |
| Mon 11:00 am | 158 | Unhealthy | 60.8 | 130 | 53 |
| Mon 2:00 pm | 157 | Unhealthy | 46.6 | 93 | 61 |
| Mon 5:00 pm | 155 | Unhealthy | 39.3 | 78 | 58 |
| Mon 8:00 pm | 152 | Unhealthy | 31.4 | 61 | 45 |
| Mon 11:00 pm | 143 | Unhealthy for Sensitive Groups | 22.9 | 52 | 35 |
| Tue 2:00 am | 128 | Unhealthy for Sensitive Groups | 20.5 | 53 | 35 |
| Tue 5:00 am | 114 | Unhealthy for Sensitive Groups | 21.7 | 65 | 34 |
| Tue 8:00 am | 102 | Unhealthy for Sensitive Groups | 23.1 | 52 | 33 |
| Tue 11:00 am | 93 | Moderate | 23.2 | 59 | 60 |
| Tue 2:00 pm | 85 | Moderate | 18.1 | 50 | 80 |
| Tue 5:00 pm | 78 | Moderate | 12.1 | 30 | 76 |
| Tue 8:00 pm | 72 | Moderate | 11 | 24 | 61 |
Every third hour of the CAMS forecast via Open-Meteo. US AQI uses rolling averages (24 h for particles, 8 h for ozone), so it moves more slowly than the hourly concentrations.
Best time to be outside in Saint-Louis tomorrow
Between 6 am and 9 pm local time, the cleanest air tomorrow is forecast around 9:00 pm (AQI 151, Unhealthy) and the worst around 6:00 am (AQI 159). The difference across the day is small, so timing matters little.
Saint-Louis vs the rest of Senegal
Across 9 Senegal cities we track, the average US AQI right now is 161 (Unhealthy). Saint-Louis at 154 is 7 points cleaner than average.
For context, the median across 3,556 cities worldwide is 58.
Air quality in cities near Saint-Louis
| City | Distance | US AQI | Category | PM2.5 µg/m³ |
|---|---|---|---|---|
| Touba | 144 km | 156 | Unhealthy | 49.6 |
| Thiès | 144 km | 163 | Unhealthy | 63.8 |
| Thiès Nones | 146 km | 163 | Unhealthy | 63.8 |
| Mbaké | 150 km | 156 | Unhealthy | 49.6 |
| Rufisque | 167 km | 165 | Unhealthy | 65.7 |
| Guédiawaye | 169 km | 165 | Unhealthy | 65 |
| Pikine | 170 km | 165 | Unhealthy | 65 |
| Dakar | 179 km | 165 | Unhealthy | 65 |
Model vs measured
We found no measured PM2.5 sensor cell within 25 km of Saint-Louis, so the numbers on this page are model estimates. Models capture regional pollution well but can miss very local sources such as a busy road or a nearby fire.
Wildfire smoke
PM2.5 is forecast to reach 73 µg/m³ in the next 24 hours while NASA satellites detected 18 fire hotspots within 300 km in the last day (nearest about 82 km away). Smoke is a likely contributor: keep windows closed, run an air purifier or HVAC filter, and check the fire map before heading out.
Advice for sensitive groups
At 154, children, older adults, pregnant people and anyone with asthma, COPD or heart disease should limit time outdoors, especially strenuous activity. A well-fitted N95/FFP2 mask cuts particle exposure; it does not filter ozone.
What the US AQI numbers mean
| US AQI | Category | What it means |
|---|---|---|
| 0-50 | Good | Air quality is satisfactory and poses little or no risk; a good time for outdoor activity. |
| 51-100 | Moderate | Acceptable for most people. Unusually sensitive people should consider shortening long or heavy exertion outdoors. |
| 101-150 | Unhealthy for Sensitive Groups | People with heart or lung disease, older adults, children and teens should cut back on prolonged or heavy exertion outdoors. |
| 151-200 | Unhealthy | Everyone should reduce prolonged or heavy exertion outdoors; sensitive groups should avoid it and keep windows closed. |
| 201-300 | Very Unhealthy | Health alert: everyone should avoid prolonged or heavy exertion outdoors, and sensitive groups should stay indoors. |
| 301-500 | Hazardous | Emergency conditions: everyone should avoid all outdoor physical activity and stay indoors with filtered air if possible. The scale tops out at 500; heavier dust or smoke is shown as 500. |
Values on this page are modelled by CAMS (Copernicus) and served by Open-Meteo; they are estimates for the area around the city centre, not readings from an official monitor.
Nearby cities
More for Saint-Louis
Air quality elsewhere
Data: Open-Meteo Air Quality API, Copernicus Atmosphere Monitoring Service (CAMS), NASA FIRMS.