SmogRank / United States

Air quality in Marshalltown, estimated

Iowa, United States. No ground monitor we can use is in this city, so these numbers are model estimates, not measurements.

≈6µg/m³
Good, estimated

Estimated PM2.5, 7-day average to 2026-09-30, about 0.4× the WHO 24-hour guideline. 30-day average ≈ 4 µg/m³.

Model estimate from the Copernicus Atmosphere Monitoring Service (CAMS), scaled by 0.82 to match 10 measured cities within 300 km over the last week. Adjusted this way, a single day lands within ×1.5 of what a monitor would read about two times in three: a guide, not a measurement. Not ranked on SmogRank's boards.

Last 30 days, estimated

152026-09-01: ≈ 6 µg/m³ (estimate)09-012026-09-02: ≈ 6 µg/m³ (estimate)2026-09-03: ≈ 4 µg/m³ (estimate)2026-09-04: ≈ 1 µg/m³ (estimate)2026-09-05: ≈ 6 µg/m³ (estimate)2026-09-06: ≈ 8 µg/m³ (estimate)2026-09-07: ≈ 4 µg/m³ (estimate)2026-09-08: ≈ 2 µg/m³ (estimate)09-082026-09-09: ≈ 7 µg/m³ (estimate)2026-09-10: ≈ 2 µg/m³ (estimate)2026-09-11: ≈ 1 µg/m³ (estimate)2026-09-12: ≈ 4 µg/m³ (estimate)2026-09-13: ≈ 1 µg/m³ (estimate)2026-09-14: ≈ 6 µg/m³ (estimate)2026-09-15: ≈ 3 µg/m³ (estimate)09-152026-09-16: ≈ 2 µg/m³ (estimate)2026-09-17: ≈ 3 µg/m³ (estimate)2026-09-18: ≈ 4 µg/m³ (estimate)2026-09-19: ≈ 5 µg/m³ (estimate)2026-09-20: ≈ 3 µg/m³ (estimate)2026-09-21: ≈ 3 µg/m³ (estimate)2026-09-22: ≈ 4 µg/m³ (estimate)09-222026-09-23: ≈ 5 µg/m³ (estimate)2026-09-24: ≈ 6 µg/m³ (estimate)2026-09-25: ≈ 8 µg/m³ (estimate)2026-09-26: ≈ 9 µg/m³ (estimate)2026-09-27: ≈ 5 µg/m³ (estimate)2026-09-28: ≈ 5 µg/m³ (estimate)2026-09-29: ≈ 2 µg/m³ (estimate)09-292026-09-30: ≈ 5 µg/m³ (estimate)
Daily means, UTC days. Dashed line: WHO 24-hour guideline (15 µg/m³).

Measured cities nearby

CityDistance7-day average
Waterloo68 km8.2 µg/m³
Ankeny68 km6.1 µg/m³
Des Moines77 km5.4 µg/m³
Cedar Rapids104 km7.0 µg/m³
Fort Dodge115 km5.7 µg/m³
Iowa City122 km6.4 µg/m³

Estimates contain modified Copernicus Atmosphere Monitoring Service information 2026. How estimates are made.