SmogRank / Countries / United States / Maryland
Most polluted cities in Maryland, United States
9 measured cities, this year; 9 above the WHO annual guideline. Worst: Baltimore at 9.0 µg/m³, #966 in the world.
9 good
- 1Baltimore 9.01.8×
- 2South Laurel 8.21.6×
- 3Hunt Valley 8.11.6×
- 4Elkton 7.41.5×
- 5Scaggsville 7.41.5×
- 6Edgewood 7.21.4×
- 7Hagerstown 6.81.4×
- 8Oxon Hill-Glassmanor 6.71.3×
- 9Rockville 6.01.2×
Good0–9.0
Moderate9.1–35.4
Sensitive groups35.5–55.4
Unhealthy55.5–125.4
Very unhealthy125.5–225.4
Hazardous225.5+
Estimated: cities without a monitor
Maryland cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.
| City | 7-day estimate |
|---|---|
| Columbia | ≈ 3 µg/m³ |
| Germantown | ≈ 3 µg/m³ |
| Silver Spring | ≈ 4 µg/m³ |
| Frederick | ≈ 3 µg/m³ |
| Waldorf | ≈ 4 µg/m³ |
| Glen Burnie | ≈ 3 µg/m³ |
| Gaithersburg | ≈ 3 µg/m³ |
| Ellicott City | ≈ 3 µg/m³ |
| Dundalk | ≈ 3 µg/m³ |
| Bethesda | ≈ 4 µg/m³ |
| Bowie | ≈ 4 µg/m³ |
| Towson | ≈ 3 µg/m³ |
| Aspen Hill | ≈ 3 µg/m³ |
| Wheaton | ≈ 3 µg/m³ |
| Bel Air South | ≈ 4 µg/m³ |
| Gwynn Oak | ≈ 3 µg/m³ |
| Potomac | ≈ 3 µg/m³ |
| Severn | ≈ 3 µg/m³ |
| North Bethesda | ≈ 3 µg/m³ |
| Catonsville | ≈ 3 µg/m³ |
| Annapolis | ≈ 3 µg/m³ |
| Hanover | ≈ 3 µg/m³ |
| Woodlawn | ≈ 3 µg/m³ |
| Severna Park | ≈ 3 µg/m³ |
| Odenton | ≈ 3 µg/m³ |
| Saint Charles | ≈ 4 µg/m³ |
| Clinton | ≈ 4 µg/m³ |
| Olney | ≈ 3 µg/m³ |
| Suitland-Silver Hill | ≈ 4 µg/m³ |
| Chillum | ≈ 4 µg/m³ |
| St. Charles | ≈ 4 µg/m³ |
| Salisbury | ≈ 4 µg/m³ |
| Randallstown | ≈ 4 µg/m³ |
| College Park | ≈ 4 µg/m³ |
| Montgomery Village | ≈ 3 µg/m³ |
| Pikesville | ≈ 3 µg/m³ |
| Parkville | ≈ 4 µg/m³ |
| Owings Mills | ≈ 3 µg/m³ |
| Bel Air North | ≈ 4 µg/m³ |
| Eldersburg | ≈ 3 µg/m³ |
Updated 2026-10-01 21:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.