San Jose: Air Pollution Today — AQI Index, PM2.5/PM10, Smog Alerts and Forecast

Latest air quality data: San Jose

Locations: San José

Pollution and air quality forecast for San José. Today is Thursday, August 27, 2026. The following air pollution values have been recorded for San José:

particulate matter (PM2.5) dust - 6 (Good)
particulate matter (PM10) suspended dust - 6 (Good)
ozone (O3) - 26 (Good)
nitrogen dioxide (NO2) - 20 (Good)
sulfur dioxide (SO2) - 4 (Good)
carbon monoxide (CO) - 434 (Good)

Real-time Air Quality Index (AQI) for San José, Wednesday, August 26, 2026: 1.

AQI 1 Good

What is the air quality in San José today? Is the air polluted in San José?. Is there smog?

Today (Wednesday, August 26, 2026) air quality is good. The air quality has no effect on health. Everyone can continue their outdoor activities normally in San José.

What is the current level of PM2.5 in San José? (particulate matter (PM2.5) dust)
Today's PM2.5 level is: 6 (Good) For comparison, the highest level of PM2.5 in San José in the last 7 days was: 8 (Monday, August 24, 2026) and the lowest: 4 (Sunday, August 23, 2026).

What is the level of PM10 today in San José? (particulate matter (PM10) suspended dust)
The current level of particulate matter PM10 in San José is: 6 (Good)

How is the O3 level today in San José? (ozone (O3))
26 (Good)

How high is the level of NO2? (nitrogen dioxide (NO2))
20 (Good)

What is the level of SO2 pollution? (sulfur dioxide (SO2))
4 (Good)

How high is the CO level? (carbon monoxide (CO))
434 (Good)

Current data Wednesday, August 26, 2026 at 7:00 PM

PM2,5 6 (Good)

PM10 6 (Good)

O3 26 (Good)

NO2 20 (Good)

SO2 4 (Good)

CO 434 (Good)

Data on air pollution from recent days in San José

index	2026-08-26	2026-08-25	2026-08-24	2026-08-23	2026-08-22	2026-08-21	2026-08-20	2026-08-19
pm25	5 Good	6 Good	8 Good	4 Good	4 Good	6 Good	5 Good	5 Good
pm10	6 Good	6 Good	9 Good	4 Good	4 Good	7 Good	5 Good	7 Good
o3	39 Good	36 Good	39 Good	34 Good	44 Good	44 Good	37 Good	36 Good
no2	11 Good	10 Good	10 Good	8 Good	6 Good	10 Good	9 Good	10 Good
so2	3 Good	4 Good	4 Good	3 Good	3 Good	3 Good	3 Good	3 Good
co	275 Good	243 Good	212 Good	181 Good	214 Good	238 Good	294 Good	292 Good

data source »

Quality of life in San José

Green and Parks in the City

San José 59%

Nicaragua: 43% Panama: 51% Honduras: 41% El Salvador: 37% Guatemala: 45%

particulate matter PM2.5

San José 24 (Moderate)

Pleasure of spending time in the city

San José 51%

Nicaragua: 52% Panama: 55% Honduras: 41% El Salvador: 40% Guatemala: 45%

particulate matter PM10

San José 27 (Moderate)

Air Pollution

San José 42%

Nicaragua: 39% Panama: 42% Honduras: 65% El Salvador: 65% Guatemala: 64%

Garbage Disposal

San José 38%

Nicaragua: 30% Panama: 33% Honduras: 22% El Salvador: 33% Guatemala: 30%

Availability and quality of drinking water

San José 78%

Nicaragua: 49% Panama: 66% Honduras: 44% El Salvador: 41% Guatemala: 39%

Cleanliness and tidiness

San José 32%

Nicaragua: 29% Panama: 37% Honduras: 20% El Salvador: 29% Guatemala: 34%

Noise and Light pollution

San José 54%

Nicaragua: 63% Panama: 60% Honduras: 49% El Salvador: 57% Guatemala: 56%

Water Pollution

San José 49%

Nicaragua: 73% Panama: 57% Honduras: 72% El Salvador: 68% Guatemala: 71%

Source: Numbeo

San Jose

Wednesday, August 26, 2026 at 7:00 PM

PM2,5 5.7 (Good)

particulate matter (PM2.5) dust

PM10 6 (Good)

particulate matter (PM10) suspended dust

O3 26 (Good)

ozone (O3)

NO2 20 (Good)

nitrogen dioxide (NO2)

SO2 3.5 (Good)

sulfur dioxide (SO2)

CO 434 (Good)

carbon monoxide (CO)

San Jose

index	2026-08-19	2026-08-20	2026-08-21	2026-08-22	2026-08-23	2026-08-24	2026-08-25	2026-08-26
pm25	5.2	4.5	6.2	3.9	3.7	7.6	5.6	5.1
pm10	6.5	5.2	7.1	4.4	4.1	9.5	6.2	5.5
o3	36	37	44	44	34	39	36	39
no2	10	9.1	10	6.1	7.9	10	10	11
so2	3.2	3	3.4	3.3	3	3.5	3.8	3.3
co	292	294	238	214	181	212	243	275

* Pollution data source: https://openaq.org () The data is licensed under CC-By 4.0

🌦️ Weather · 16-day Forecast — Costa Rica

16-day weather forecast for Costa Rica: today around 24°C (rain), lows near 17°C. Daily temperature and conditions, updated every day. A moderate breeze (about 10 km/h) is partially dispersing pollutants today.

☀️ UV Index · 16-day Forecast — Costa Rica

The UV index in Costa Rica today is 9.3 (very high) — unprotected fair skin can burn in about 20 minutes.

Frequently asked questions

Is the air safe to breathe in San José today?

The current average PM2.5 across San José is about 6 µg/m³, rated “Good”. Air quality is good — outdoor activities are fine for everyone.

What is the current PM2.5 level in San José?

Right now PM2.5 in San José averages about 6 µg/m³ (“Good”). PM2.5 are fine particles small enough to reach the lungs and bloodstream.

Which day last week had the worst air in San José?

Over the past week, the highest daily PM2.5 in San José was recorded on Monday, August 24 (about 8 µg/m³).

What is the UV index in San José today?

The UV index in San José today is 9.3 (very high) — unprotected fair skin can burn in about 20 minutes.

Does today's wind help disperse smog in San José?

A moderate breeze (about 10 km/h) is partially dispersing pollutants today.

How is air quality measured?

Air quality here is based on PM2.5 — the concentration of fine particulate matter in µg/m³. Lower values mean cleaner air. Data is updated daily from Open-Meteo.