Air quality comparison · United States, 1741.1 mi (2802 km) apart
Chicago vs Los Angeles Air quality index (AQI) today
Los Angeles has cleaner air than Chicago right now: AQI 39 (Good) against 114 (Unhealthy for sensitive groups).
That puts them in different EPA bands, so the health advice differs today. But over the past 7 days, on modeled daily averages, Chicago averaged AQI 34 against 57, and it was the cleaner of the two on 7 of those days. Los Angeles has lost more forest since 2001. Chicago has more tree cover.
United States
AQI 114
Unhealthy for sensitive groups
Cleaner right now
- PM2.5
- 40.6 µg/m³2.7× WHO guideline
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 09:00 local
United States
AQI 39
Good
Cleaner right now
- PM2.5
- 7.1 µg/m³
- Main pollutant
- PM2.5
- Source
- Ground station
- Reading
- Nov 11, 07:00 local
Updated . Lower is better on the US EPA index: 0–50 is Good, above 300 is Hazardous. Measured by Airleaf.
Chicago114Los Angeles39
Head to head
Chicago vs Los Angeles at a glance
Chicago and Los Angeles are level, each ahead on 3 of 6 measures. The better figure in each row is marked.
| Chicago | Los Angeles | |
|---|---|---|
| Air quality nowUS AQI. Lower is better. | 114 | 39 (better) |
| PM2.5Fine particles, µg/m³. | 40.6 | 7.1 (better) |
| Past week's averageUS AQI, 7 days. | 34 (better) | 57 |
| Forest lost since 2001Within 10 km of the center. | 5 acres (2 ha) (better) | 304 acres (123 ha) |
| Tree coverWithin 1.2 mi (2 km) of the center. | 8.2% (better) | 4.5% |
| Trees still neededTo reach a healthy canopy. | 82.9K | 80.0K (better) |
Air quality today
What is the air like in Chicago and Los Angeles right now?
Los Angeles has cleaner air than Chicago right now: AQI 39 (Good) against 114 (Unhealthy for sensitive groups). PM2.5 is setting the index in both.
Chicago's PM2.5 is about 2.7× the WHO's 24-hour guideline of 15 µg/m³.
Both readings come from nearby ground stations.
ChicagoLos Angeles
Concentrations at the same moment as the index above, for the pollutants both places report. Lower is better. The dark marks on the PM2.5 and PM10 rows show the WHO's 24-hour guidelines (15 and 45 µg/m³).
The past week
Which had cleaner air over the past 7 days?
But over the past 7 days, on modeled daily averages, Chicago averaged AQI 34 against 57, and it was the cleaner of the two on 7 of those days. A single reading can catch a city on a bad afternoon; the week says whether it was the weather or the place.
- Cleaner days
- Chicago7Los Angeles0
- Average AQI
- Chicago34Los Angeles57
- Worst day, AQI
- Chicago52Los Angeles70
The daily numbers (7 days)
| Day | Chicago | Los Angeles |
|---|---|---|
| Nov 4 | 27 | 67 |
| Nov 5 | 32 | 57 |
| Nov 6 | 11 | 47 |
| Nov 7 | 32 | 46 |
| Nov 8 | 35 | 52 |
| Nov 9 | 47 | 60 |
| Nov 10 | 52 | 70 |
Daily averages from the CAMS atmospheric model for both places, so the week compares like with like. They can differ from today's reading at the top of the page wherever that comes from a ground station.
What it means today
Is it safe to go outside in Chicago and Los Angeles today?
Chicago (AQI 114, Unhealthy for sensitive groups): Sensitive groups should limit long or intense outdoor activity.
Los Angeles (AQI 39, Good): Air quality is satisfactory for everyone.
Exercise outdoors
- Chicago
- Children, older adults and people with asthma or heart disease should cut down long or hard exercise.
- Los Angeles
- A good day to be active outside.
Windows
- Chicago
- Close them to keep the outside air out.
- Los Angeles
- Open them to air the house.
Masks
- Chicago
- Sensitive groups: an N95 outdoors.
- Los Angeles
- Not needed.
Air purifier
- Chicago
- Run one, especially in bedrooms.
- Los Angeles
- Not needed.
Against everywhere else
How do Chicago and Los Angeles compare with the rest of the world?
Right now Chicago's air is cleaner than 17% of the 5,420 places Airleaf tracks, and Los Angeles's is cleaner than 70%. Within United States, that is 2% and 51% of its 308 measured places.
Cleaner air than…
- Chicago
- Beats 17%
- Los Angeles
- Beats 70%
More tree cover than…
- Chicago
- Beats 17%
- Los Angeles
- Beats 9%
Includes model estimates as well as station readings, so it can differ from our most polluted and cleanest air rankings, which use station readings only.
Deforestation · 2001–2025
Which has lost more forest, Chicago or Los Angeles?
Los Angeles has lost more: about 304 acres (123 ha) of forest within 10 km of its center from 2001 to 2025, against 5 acres (2 ha) around Chicago. 9 acres (4 ha) of that was cleared for good, for farms, mines or towns.
Measured within 10 km of each center, from the yearly satellite maps of forest loss: a wider circle than the one for tree cover, because forest is usually lost at a city's edges.
Worst year: 2003, with under 1 ha lost.
Worst year: 2007, with 289 acres (117 ha) lost.
| Chicago | Los Angeles | |
|---|---|---|
| Forest lost since 2001Cleared, burned or logged. | 5 acres (2 ha) (better) | 304 acres (123 ha) |
| Share of its forestOf what it had in 2000. | under 1% (better) | 53% |
| Cleared for goodTurned into farms, mines or towns. | under 1 ha (better) | 9 acres (4 ha) |
| Recent trend2021–2025 against the five years before. | Too little to call | Too little to call |
| Main known cause | Towns and roads (42%) | Wildfires (96%) |
Satellite timelapses
Watch both change, year by year
A clear satellite photo a year of the land around each city. Press play, turn on the forest cleared since the first year, or drag the before and after.
Chicago
2018: satellite photo from August 2018 of a 5 × 5 km area in the city center.
Los Angeles
2017: satellite photo from July 2017 of a 5 × 5 km area in the city center.
Trees
Which has more trees, Chicago or Los Angeles?
Chicago has more tree cover: 8.2% of the land within 1.2 mi (2 km) of its center against 4.5% around Los Angeles, or about 25,375 trees against 14,123.
The dark mark is each place's canopy target: 30% of the land, raised where air quality is poor.
| Chicago | Los Angeles | |
|---|---|---|
| Trees standingEstimated from the canopy area. | 25.4K (better) | 14.1K |
| Trees still neededTo reach the target. Fewer is better. | 82.9K | 80.0K (better) |
| CO₂ absorbed each yearBy the trees already standing. | 558K kg (better) | 311K kg |
Tree cover on the satellite image
The same 1.2 mi (2 km) radius around each center, with the tree cover the satellite found marked on it.
Reading these numbers
How this comparison is made
Air quality index
The US EPA index, computed from current pollutant concentrations: ground stations where a place has them nearby, and the CAMS atmospheric model everywhere else. It moves hour to hour, so it is a snapshot rather than a verdict on either place. The guideline marks are from the WHO's 2021 air quality guidelines.
Trees and forest
Tree cover is the share of ground under canopy within 1.2 mi (2 km) of each center, read from Sentinel-2 satellite imagery at 10 m detail. It measures that circle, not the whole municipality, which is what makes the two comparable. Forest loss comes from the University of Maryland's Global Forest Change maps.
More on the method on the About Airleaf page.
Frequently asked
Chicago vs Los Angeles: your questions answered
Is Los Angeles cleaner than Chicago?
On air quality, yes, right now: Los Angeles reads AQI 39 against 114, a gap of 75 points on the US EPA index. This is a live reading rather than an annual average, so it can reverse within a day. But over the past 7 days, on modeled daily averages, Chicago averaged AQI 34 against 57, and it was the cleaner of the two on 7 of those days.
Is it safe to exercise outdoors in Chicago and Los Angeles today?
In Chicago, at AQI 114: Sensitive groups should limit long or intense outdoor activity. In Los Angeles, at AQI 39: Air quality is satisfactory for everyone.
Which has lost more forest, Chicago or Los Angeles?
Los Angeles has lost more: about 304 acres (123 ha) of forest within 10 km of its center from 2001 to 2025, against 5 acres (2 ha) around Chicago. 9 acres (4 ha) of that was cleared for good, for farms, mines or towns.
Which has more trees, Chicago or Los Angeles?
Chicago has more tree cover: 8.2% of the land within 1.2 mi (2 km) of its center against 4.5% around Los Angeles, or about 25,375 trees against 14,123. Both figures describe the same-sized circle of ground around each center, not the whole municipality.
How many more trees do Chicago and Los Angeles need?
Chicago needs about 82,932 more to reach its canopy target of 35%, and Los Angeles about 80,030 to reach 30%. The target starts at 30% of the land and rises where air quality is poor.
Are Chicago and Los Angeles measured the same way?
The method is the same: the US EPA index for air, and Sentinel-2 satellite imagery at 10 m detail over an identical radius for trees. Both readings come from nearby ground stations. Nothing is adjusted for population, city limits or climate.
How often does the Chicago vs Los Angeles comparison update?
The air readings refresh about once an hour, and each reading's local time is shown at the top of the page. Tree cover comes from the latest clear satellite image of each area (Sep 11, 2026 and Sep 14, 2026), and the forest figures are published yearly.
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