Long Beach, CA Air Quality Index (AQI) Today

The number above is Long Beach’s own, not a rounding error off Los Angeles next door. It decides something concrete. The walk on the Shoreline path. Whether soccer practice moves indoors. Whether the windows stay open tonight against the diesel drifting off the harbor. This page tracks the air quality Long Beach itself has actually breathed over the past 30 days, not just the figure sitting above it. Set your own line and let a text tell you when the port air crosses it.

Long Beach’s last 30 days, not just today

A single reading can’t say whether today is ordinary or a genuine spike. This chart rebuilds the air quality Long Beach has actually seen over the trailing 30 days. It pulls from the same hourly AQI feed as the number above. A running count tracks days above AQI 100 in the last 12 months. Most cities on this list show clear spikes: a fire month, an inversion stretch, then a quiet baseline. The air quality Long Beach reports runs flatter than that. Its main source doesn’t take a season off, so the shape here reads more like a steady hum than a sharp peak-and-trough.

Why is it hazy in Long Beach today?

Three explanations cover most hazy-but-moderate days here. A 24-hour average can smooth out one genuinely rough hour. Smoke can sit aloft, above whatever’s actually measuring ground level. Or the monitoring station stands in for a stretch of metro it isn’t really next to. That’s a real risk in Long Beach, where a city-centroid reading and a harbor reading can differ more than in most single-mechanism metros.

Long Beach also sits inside the same South Coast basin marine layer that traps pollution against the coastline further north. Los Angeles’s own page covers the basin mechanics in full: the mountain ring, the marine layer, the Santa Ana winds that occasionally scour it clean. None of that makes a hazy sky here fake — it means the number is one average, from one station, standing in for a stretch of coastline with a working port at the center of it. Port exhaust, basin geography, and an averaged reading breaks the causes down.

A continuous source makes a flat curve. Search volumes, not AQI readings — bars are neutral blue-grey with the peak month in accent blue, never EPA band colours, so demand data can never be read as a measurement of the air.

What is causing the bad air in Long Beach?

Together, the Port of Long Beach and the neighboring Port of Los Angeles are the two busiest container ports in the United States. That’s IQAir’s own research. Ships, trucks and cargo-handling equipment run on diesel most days of the year, making the port a continuous source, not an event. Unlike a wildfire month or a cold-air inversion, there’s rarely one bad week to point to here.

The same research credits the ports’ 2006 Clean Air Action Plan with cutting particulate matter (PM) from port operations by 87%. Nitrogen oxides are down 58% since it took effect. Even so, the two ports together still produce an estimated 100 tons of smog daily, with little further improvement measured since 2011. That gap — real progress, real ceiling — is why the verdict below has to work on an ordinary Tuesday, not just a bad one.

Is the air safe to breathe in Long Beach today?

A reading taken at the Long Beach harbor and one taken at the city centroid can genuinely disagree. Port traffic and ship emissions sit heaviest right at the water. Go on an ordinary day. Short and unloaded: the short dog loop, errands instead of yard work near the port side of town. Don’t go once trimming isn’t enough.

On the EPA scale, everyone gets warned starting at 151, Unhealthy. 201 through 300, Very Unhealthy, is that same warning turned up, not a new group added to it. Past roughly 200 — harbor reading or centroid reading — the outing waits.

What AQI should you stay inside?

Personal thresholds here shift with which of the two readings — harbor or centroid — a person is actually breathing. An asthmatic runner logged 156 runs against AQI and drew the line at 60. Past it, “my lungs struggle regardless of how well I’ve trained,” even though EPA calls nothing under 100 unhealthy.

That log: 87% of runs under 50 went fine, 42% between 50 and 70, just 12% past 70. A r/Marathon_Training runner sets theirs far higher: “I’ll run in up to 110 because…error bars.” Parents this project has seen online land near 100.

Wildfire smoke pulls that whole table down about one EPA band, stacked on top of whatever the port and harbor traffic already contribute. 101–150 is the EPA’s orange band, Unhealthy for Sensitive Groups, attributed and not a verdict on any one reader.

California hasn’t put a number on this for schools or daycares, at least nothing this project can confirm. Washington and Minnesota are the exceptions. The two states that publish a threshold covers both.

Indoors, a Corsi-Rosenthal box or a portable HEPA purifier is the default — one community builder priced a 12x14 bedroom box at $130. A MERV-13 swap needs a static-pressure check from a licensed tech first; it isn’t automatic for a system near the harbor’s heavier particulate mix. Why a monitor beats a purifier as a first purchase sets out the order.

EPA AirNow’s own colours and breakpoints. The three marked cutoffs are not EPA guidance and not Long Beach rules — each is one reader’s or one institution’s own line.

Why our number may not match what you are seeing and smelling

The mismatch runs in two directions here. A hazy sky with a moderate reading is usually the 24-hour average, or a station standing in for the wrong stretch of coastline. A clear, still day can still carry a bad number. Ground-level ozone and diesel particulate near the port don’t always announce themselves to the eye or nose the way visible smoke does.

shows the station behind today's number, its distance from the harbor, and the nearby PurpleAir sensor count — PM2.5 and PM10 both factor into the port reading. This is likely the sharpest station-distance case on this whole site: a monitor sited toward the city center can under-report the neighborhoods that sit right against the port complex, sometimes by a meaningful margin. [Why a city-center monitor under-reports the port edge](/methodology/) is documented in full.

What Long Beach looks like from across the basin

Los Angeles has its own folk indicator for a genuinely clear day: whether Catalina Island is visible from the Getty Center, up in the hills. During the 2020 lockdown, traffic was down across the whole basin. Hikers there reported something rarer — seeing all the way to Long Beach, not just Catalina.

Catalina from the Getty is the sight regulars already expect. Long Beach alongside it was the surprise, worth noting because the port here runs on the same continuous, non-seasonal schedule. An ordinarily hazy sightline down this stretch of coast may have less to do with weather than with a source that sits right at the harbor, working every day of the year.

The same basin, the same mechanism elsewhere

Irvine sits further inland in the same South Coast basin, catching the marine layer without the port traffic. The port-and-industrial-corridor mechanism itself isn’t unique to Southern California: Houston runs a similar refinery-and-ship-channel setup, and Oakland has its own version across the Bay.

Pittsburgh’s Allegheny valley traps industrial emissions the same way a coastal marine layer traps port diesel. Different geography, same lesson: a constant source needs a verdict that works on an ordinary day, not just a bad one.

FAQ

What’s the air quality forecast for Long Beach tomorrow?

Marine layer, wind direction and port activity can all shift a forecast within hours. Treat it as a direction, not a lock, and recheck the morning of.

What’s the UV index in Long Beach today?

UV runs on its own scale, separate from AQI. A hazy, moderate-AQI day at the coast can still be a high-UV day. A mediocre air quality reading isn't a reason to skip sunscreen either.

Who has the worst air quality in the US right now?

See how Long Beach ranks today against every tracked city. Its air quality moves less with the season than most, because the port doesn’t slow down for winter or summer.

What is in the air in Long Beach right now?

That's today's specific reading. Diesel particulate matter (PM2.5) from ships, trucks and cargo equipment is the steady baseline here; ground-level ozone from the wider basin adds to it on hot, still afternoons.

What AQI should you not exercise in?

There’s no single number — it depends on who’s asking and how long they’re out. Runners in the community cite up to 110. Parents cut outdoor time around 100. One asthmatic runner’s own 156-run log put their cutoff at 60. Wildfire smoke pushes all of those down roughly one EPA band.

Why does it smell like smoke outside in Long Beach?

Wildfire smoke here is almost always drifting in from a fire elsewhere in the basin or further north, not a local one. If a specific fire is active, What a plume does that port air doesn’t is the briefing.