Worst air pollution Katwijk, today and tomorrow

Today (21 July): Air quality in Katwijk is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 3:00 PM (O3: 24.8/100).
Tomorrow (22 July 2026): Air quality in Katwijk is fair. All pollutants stay as today. Pollution peaks around 7:00 AM (O3: 24.5/100). Airmine updates local air quality forecasts four times daily.

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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team

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Katwijk's air quality benefits from its direct North Sea coastal position in South Holland, with powerful North Sea westerlies providing reliable and consistent maritime ventilation along the Dutch coast. Vehicle traffic on the N206 and Katwijk's residential and beach resort character are the primary local sources, while the Katwijk aan Zee beach and the open North Sea fetch generally maintain excellent to good coastal conditions and keep Katwijk among the Netherlands' cleaner coastal communities.

Today - 21 July | Pollution peaks at 15:00

AQI:

Fair

24.8/100

PM2.5 (fine particles):

Good

10.3/100

PM10 (coarse particles):

Good

3.9/100

NO2 (nitrogen dioxide):

Good

5.2/100

O3 (ozone):

Fair

24.8/100

SO2 (sulfur dioxide):

Good

1.5/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

1.4/100

PM1 (ultrafine particles):

Good

6.7/100

Levels show the poorest local air quality during the day

Tomorrow - 22 July | Pollution peaks at 07:00

AQI:

Fair

24.5/100

PM2.5 (fine particles):

Good

10.7/100

PM10 (coarse particles):

Good

4.4/100

NO2 (nitrogen dioxide):

Good

3.4/100

O3 (ozone):

Fair

24.5/100

SO2 (sulfur dioxide):

Good

1.1/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

1.3/100

PM1 (ultrafine particles):

Good

5.4/100

Pollen forecast in Katwijk

View pollen forecast

Frequently Asked Questions

Is air quality bad in Katwijk right now?

On 21 July 2026, overall air quality in Katwijk is fair. AQI is the main air quality indicator at 24.8/100. Pollution peaks around 3:00 PM (O3: 24.8/100).

Will air quality be worse tomorrow in Katwijk?

On 22 July 2026, air quality conditions in Katwijk will be similar to today, with AQI forecast at fair at 24.5/100. Pollution peaks around 7:00 AM (O3: 24.5/100).

When is air pollution at its worst in Katwijk?

Katwijk typically sees the birch, oak, and alder pollen peak over the spring and early-summer period, alongside calm, warm days when traffic on the N206 and industry emissions accumulate, as the periods to watch; the flat polder terrain and sea proximity generally support decent air movement. Outside these windows, Katwijk generally stays close to the national average for air quality.

Are air quality levels in Katwijk based on measurements or forecasts?

It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.

Why doesn’t the forecast always reflect wildfire impacts?

Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.

During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.

Want to see air quality forecasts for other cities in Netherlands?

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Data provided by Airmine — Last update: 21 July 2026 at 16:20 CEST (Data is updated four times daily.)

This forecast is produced independently using Airmine's own atmospheric data and models.

Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.

For long term forecasts and maps, see the Airmine app