July 05, 2018

Profound Impacts of Fireworks on Visibility and Air Quality

The visibility this morning was greatly reduced compared to yesterday and fireworks smoke played a major role.

Here is view from the Seattle PanoCan looking towards the Cascades at 9:30 AM this morning (Thursday, July 5).  Very hazy with the foothills barely visible.  The haze is from fireworks.

The day before at the same time (July 4th, of course).  Some clouds aloft, but MUCH better visibility.  You can even see Mt. Rainier.

Now you don't have to take my word for the existence of plumes of smoke from fireworks.... lets take a look at the observations taken by the Puget Sound Clean Air Agency.  Here is the amount of small particles in the air (PM2.5) on Seattle's Beacon Hill.  Huge and sharp increase of particles during the evening of July 4th, to values over 100 (micrograms per cubic meter).  This is in the unhealthy level.

But why was in hazy this morning looking east?  To figure this out, let's examine the particles levels at Bellevue (brown line) and North Bend, near the Cascade foothills (green line).   Big increase during the evening of the fourth, but the levels stayed relatively high!

I suspect a lot of the smoke over the populated area near Puget Sound got pushed towards the east this morning.  In fact, the time-height cross section of wind and temperature at Seattle Sand Point provided by Puget Sound Clean Air Agency (see below) does suggest this (below).  The winds were easterly during the afternoon  but switched to westerly at low levels for several hours overnight  (heights are in meters ASL, time in UTC increases to the left)

And don't think Seattle was the only place with smoke.  It was worse in Tacoma and Marysville, home of Boom City, had a problem as well (see below).

Last time I was watching the Lake Union fireworks display with students, staff, and faculty on the top of my building, and the smoke became increasingly extensive during the short show. 

By 11 PM, the smoky scene was beginning to look apocalyptic.

Several people told me they felt cold-like symptoms this morning from the left-over smoke.  In any case, air quality will improve rapidly now as a Pacific front moves through bringing an influx of clean, marine air.   

Finally, there may be a superior replacement for the smokey fireworks---performances of hundreds of drones with LED lights.    Check out this video to see what I mean.


  1. There will be drone light shows at the Arlington Flyin this Friday and Saturday. http://www.arlingtonflyin.org/night-balloon-glow-and-drone-show/

  2. Tried to get away from the fireworks high above Snoqualmie Pass. We were surprised by the size of the displays from the developments at the summit and Alpental, with loud booms that lasted to almost midnight! It was was fun at first, starting at 9:30 or so, but got old fast. Left early this morning, stopped at North Bend and the haze was so thick that Si was heavily obscured, we thought there might be a wildfire nearby. The air quality at the pass was noticeably worse.

  3. I had an unexplained cold like symptoms this morning. Wonder if it was the smoke. I wonder if one could take geo-located google searches for cold-like symptoms and cross-reference with smoke dispersion patterns to look for a correlation which would support this hypothesis. Could be a cool study that makes the case more convincing. Could also try to compare searches for symptoms after other similar celebratory days which are likely to involve a good bit of drinking but less fireworks. Not my area of expertise, but I think there are a lot of people at the UW who are good with the big data mining of google search data.

  4. Looks like we had below normal temps for June???

  5. Not on topic, but the temperature reached 95 degrees F this week ... in Siberia.

    Arctic Amplification is messing with the polar jet stream, promoting extreme weather events according to this article:
    Extreme Heat Event in Northern Siberia and the coastal Arctic Ocean This Week

  6. Thanks for focusing attention of the detrimental affects of fireworks on air quality.

  7. Let me see....
    -Air quality down.
    -Wildfires up.
    -Injuries up.
    -Fireworks trash all over.
    And not discussed but another thing to consider: noise and its effects on people and animals, both domestic and wild.

    So why is it that we have to recreate a war zone every July 4th?
    A radical idea: Let's declare a cease fire and celebrate peace and quiet next year and watch what happens to the stats!


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