Maryland air quality

Middle River, Maryland Air Quality

Baltimore County39.334, -76.439

The nearest monitor to Middle River, at Essex, 2 miles away, measured an index of 27 at Mon, 3:00 PM EDT, which is Good for ground-level ozone. Maryland Department of the Environment forecasts Good for Metro Baltimore today and Good tomorrow. NOAA’s analysts drew medium wildfire smoke over the town today.

Measured now
27 · Good
Today
30 · Good
Tomorrow
17 · Good
Pollutant
Ozone

Fine particles on the map

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Middle River, Maryland. Open it for the live map, where it pans and zooms.

Forecast fine particulate matter from NOAA’s National Air Quality Forecast Capability over Middle River, Maryland Open the live map with the particulate forecast

Map layer from NOAA National Air Quality Forecast Capability. Boundaries from the Iowa Environmental Mesonet.

Alerts in force

An Air Quality Alert is issued by the National Weather Service on behalf of a state or local agency when pollution is expected to reach a level that harms health. An Air Stagnation Advisory means the air will not move enough to clear what is already in it.

None are in force near Middle River right now. All Maryland warnings.

Now

Good

Nearest monitor
Essex, 2 miles away (site 240053001)
Index measured
27 · Good
Measured at
Mon, 3:00 PM EDT
Ozone
34 ppb
Reporting area
Metro Baltimore, MD, 13 miles away
Reported by
Maryland Department of the Environment
Area index
27 · Good

Measured, not modeled. AirNow observations are preliminary until the operating agency certifies them, which happens months later.

Today and tomorrow

Maryland Department of the Environment's own forecast for Metro Baltimore, written by a forecaster rather than read off a model.

DayCategoryIndexPollutant
TodayGood30Ozone
TomorrowGood17PM2.5
Wednesday, September 23Good17PM2.5
Thursday, September 24Good17PM2.5

The forecaster’s discussion

Written by Maryland Department of the Environment for Metro Baltimore and filed with AirNow.

Ozone forecasting for 2026 ends today. Fine particle forecasting continues year-round. Early fall-like weather on Saturday will deliver clean conditions on mild and dry northeasterly winds. Good air quality results. Winds switch back to the south on Sunday. Humidity will increase as a warm front pushes towards the region, bringing with it dirtier air from our south. This may lead to a few higher hours of perhaps Moderate AQI due to fine particles on Sunday afternoon. However, overall exposure is expected to remain relatively low, with Good AQI expected for the daily average Sunday. Another cold front moves through late Sunday, delivering excellent air quality for Monday which will persist into mid-week. Fine particle concentrations are expected to be quite low, resulting in Good air quality for the region through the middle of next week. For the latest air quality information, please visit our website here. -MDE

Hour by hour

NOAA’s National Air Quality Forecast Capability, bias-corrected against monitors, for this town’s own coordinate. The worst hour ahead is an index of 43, Good, around Mon, 9:00 PM EDT, from the run issued Mon, 8:00 AM EDT. This is a model, not a measurement.

HourIndexCategoryPM2.5Ozone
Mon, 10:00 AM EDT33Good5.6
Mon, 11:00 AM EDT27Good4
Mon, 12:00 PM EDT20Good2.6
Mon, 1:00 PM EDT14Good1.6
Mon, 2:00 PM EDT9Good1
Mon, 3:00 PM EDT6Good0.5
Mon, 4:00 PM EDT23Good0.725.9
Mon, 5:00 PM EDT25Good2.127.1
Mon, 6:00 PM EDT26Good4.828.7
Mon, 7:00 PM EDT28Good6.830.2
Mon, 8:00 PM EDT38Good8.631.4
Mon, 9:00 PM EDT43Good8.932.3
Mon, 10:00 PM EDT37Good5.733.3
Mon, 11:00 PM EDT31Good2.233.5
Tue, 12:00 AM EDT31Good0.933.3
Tue, 1:00 AM EDT31Good0.433
Tue, 2:00 AM EDT30Good0.732.1
Tue, 3:00 AM EDT29Good1.831.1
Tue, 4:00 AM EDT28Good2.930.2
Tue, 5:00 AM EDT27Good2.929.6
Tue, 6:00 AM EDT26Good228.9
Tue, 7:00 AM EDT25Good2.528
Tue, 8:00 AM EDT24Good2.926.9
Tue, 9:00 AM EDT23Good2.525.3
Tue, 10:00 AM EDT21Good1.723.4
Tue, 11:00 AM EDT20Good1.422.1
Tue, 12:00 PM EDT19Good0.621
Tue, 1:00 PM EDT18Good0.819.3
Tue, 2:00 PM EDT15Good1.417
Tue, 3:00 PM EDT14Good1.315.5
Tue, 4:00 PM EDT13Good1.514.5
Tue, 5:00 PM EDT13Good0.914.2
Tue, 6:00 PM EDT13Good1.514.3
Tue, 7:00 PM EDT13Good1.214.6
Tue, 8:00 PM EDT14Good0.915.4
Tue, 9:00 PM EDT14Good215.7
Tue, 10:00 PM EDT15Good2.716.3
Tue, 11:00 PM EDT15Good2.116.6
Wed, 12:00 AM EDT16Good1.217.2
Wed, 1:00 AM EDT17Good0.718.3
Wed, 2:00 AM EDT18Good1.119.4
Wed, 3:00 AM EDT18Good219.5
Wed, 4:00 AM EDT17Good2.918.7
Wed, 5:00 AM EDT17Good2.618.3
Wed, 6:00 AM EDT17Good1.518.5
Wed, 7:00 AM EDT17Good2.618.1
Wed, 8:00 AM EDT16Good2.417.3
Wed, 9:00 AM EDT15Good216.1
Wed, 10:00 AM EDT14Good1.715
Wed, 11:00 AM EDT13Good1.314.8
Wed, 12:00 PM EDT14Good2.315.6
Wed, 1:00 PM EDT15Good2.316.9
Wed, 2:00 PM EDT16Good3.517.9
Wed, 3:00 PM EDT20Good4.519.9
Wed, 4:00 PM EDT20Good2.822
Wed, 5:00 PM EDT21Good224
Wed, 6:00 PM EDT23Good2.125.9
Wed, 7:00 PM EDT25Good2.227.2
Wed, 8:00 PM EDT25Good2.527.9
Wed, 9:00 PM EDT25Good1.427.5
Wed, 10:00 PM EDT24Good2.126.6
Wed, 11:00 PM EDT23Good2.525.6
Thu, 12:00 AM EDT22Good2.624.6
Thu, 1:00 AM EDT21Good2.523.5
Thu, 2:00 AM EDT19Good3.321.6
Thu, 3:00 AM EDT21Good4.619.7
Thu, 4:00 AM EDT24Good4.918.1
Thu, 5:00 AM EDT21Good3.217.7
Thu, 6:00 AM EDT16Good1.617.8
Thu, 7:00 AM EDT16Good1.517.6
Thu, 8:00 AM EDT16Good1.417.4

Fine particles in micrograms per cubic meter, ozone in parts per billion as an 8-hour average. The index for each hour is EPA’s: the ozone figure is already the 8-hour average the ozone index is defined on, and the particle figure is run through EPA’s NowCast, which is how an hourly PM2.5 concentration becomes an index.

Smoke

NOAA’s Hazard Mapping System analysts drew medium smoke over Middle River in satellite imagery today (Mon, 11:00 AM EDT to Mon, 1:00 PM EDT). That is smoke seen from above; it is not always smoke at ground level.

NOAA’s model forecasts near-surface smoke peaking at 0.2 µg/m³ around Sun, 11:00 PM EDT.

Smoke on the radar over Middle River

What this means

Good

Air quality is satisfactory, and air pollution poses little or no risk.

Who is affected
Nobody is expected to be affected.
What to do
It is a good day to be outside.
Index range
0 to 50

Category descriptions are the Environmental Protection Agency’s own.

What these numbers are. An index beside a monitor’s name is a measurement, published hourly by AirNow and preliminary until the operating agency certifies it. A category for today or tomorrow is a state or local agency forecaster’s own forecast for a reporting area. An hourly index is NOAA’s air quality model on a five-kilometer grid, not a reading from any instrument. Where a town has no monitor within reach, only the model figures appear, and the page says so.

Nearby

The nearest towns with a page of their own, closest first.

Weather forecast for Middle RiverWarnings in Baltimore CountyLive radar over Middle RiverMaryland air quality

Sources

Observations and daily forecasts from AirNow, the US Environmental Protection Agency’s program with NOAA, the National Park Service, NASA, tribal, state and local agencies. Hourly forecasts from NOAA’s National Air Quality Forecast Capability. Smoke analysis from NOAA’s Hazard Mapping System. Alerts from the National Weather Service. Index categories and breakpoints are EPA’s, as revised in 2024.