The Science of Fireworks

Washington, D.C. July 4th fireworks

It’s the sign that Fourth of July is right around the corner – fireworks. The light displays decorate the skies across the United States every year to celebrate our Independence Day. All of the beauty and marvel that comes with fireworks displays is actually due to science.

Chemistry is behind the vivid displays of fireworks in a few ways. The basic formula to create fireworks combines an oxygen rich chemical with burning fuel. Additional chemicals within the package can create the different colors seen in the displays. Strontium will create red colors, titanium causes white and copper produces fireworks with a blue tint. Blue is one of the more difficult colors to achieve because the copper needs to reach a certain temperature (after all, what’s Fourth of July without red white and blue?). Fireworks produce an exothermic reaction, which means that they release energy as heat. That heat turns into the lights and colors we see in the sky.

While chemistry is responsible for many processes during fireworks explosions, physics also plays its own role. The final height of the firework depends on its initial speed. Fireworks are launched using force from an explosion, accelerating it upward. Pressure causes the fireworks to fly upwards and eventually explode outward.

Hundreds of people are injured due to fireworks. Even the handheld sparklers can burn at a temperature of 2,000°F+. Those types of temperatures can melt certain metals, so it would do similar damage to skin.

Meteorology can also affect a fireworks show. Higher humidity may tone down the otherwise vivid colors that decorate the sky. Lightning could hit an unused firework and cause injuries to any bystanders. Strong winds pose a fire hazard – and drought makes things even more dangerous. Too little wind cannot clear smoke after the explosions. When the temperature increases with height (called an “inversion”) instead of decreasing as it usually does, smoke from the fireworks display could decrease viewing quality.

Eastern Iowans should prepare for isolated showers and storms for the afternoon and evening of Fourth of July 2018.


Posted under Educational, Optics

This post was written by Rachael Peart on July 3, 2018

Monday Sundogs

The fresh fallen snow from Sunday night, coupled with the blowing snow and cold Monday and breaks in the clouds late in the day, many of us saw sundogs across eastern Iowa.  Here are some of the viewer photos sent in Monday.

Jodi Zimmer – Waterloo


Hannah Renae – La Porte City


Amber Barber


Brandi Thompson – Waverly


Carey Cowell – Plainfield


David Stuber


Deb Lyon – Buchanan County


Donna Rosonke – New Hampton


Vicki Van Hauen – Cedar Falls


Toni Hinrichs – Nashua


Roxy Anderson – Cedar Falls


Mike Weber – Dike


Lisa Hovey – Waterloo


Joseph Warrior


Laurie DeGroote – Butler County


Posted under Miscellaneous, Optics, Photo

This post was written by Kyle Kiel on January 15, 2018

Saturday Sun Dogs

This weather goes to the “sun dogs.”  A lot of times when we get really cold temperatures in the winter, we see sun dogs around sunrise and/or sunset.  This happens when the light from the sun refracts off of ice crystals in the upper levels of the atmosphere, generally within cirrus clouds.

Here are some photos set in from viewers.

Jenny Emergy – Waucoma


Karlee Ihde – West Union


Misty Morrissey – Fort Atkinson


Barb Schwamman – Osage, IA


Joyce Meyer – Spillville


Bob Hemesath – Festina


Barb Schwamman – Osage, IA

Jason Guyer – West Union


Ashley Haw – Osage


Lori Luebbers – Sumner


Posted under Optics, Photo

This post was written by Kyle Kiel on December 30, 2017

Northern Lights Tuesday Night

On Tuesday evening and night, parts of eastern Iowa may have looked north and seen the Northern Lights.

Northern Lights forecast Tuesday, November 7, 2017

Here is a photo of the northern lights in Bryant in Clinton County from Tuesday night.


The forecast for Wednesday evening viewing is similar for eastern Iowa:

Northern Lights forecast Wednesday, November 8, 2017

If you would like to try to see the Northern Lights, look north tonight in areas away from city lights.


Posted under Astronomy, Optics, Photo

This post was written by Rachael Peart on November 8, 2017

Double Rainbow

Several KWWL viewers spotted a double rainbow across parts of eastern Iowa Saturday evening.  Here are some of the photos submitted.

Photo: Allyson Crotty near Dike


Photo: Jessi Bakker in Dike


Photo: Kevin Sawyer in Dike


Photo: Mary Butterfield in Wellsburg


Photo: Kevin Sawyer in Dike


Photo: Mindy Peters in Grundy Center


Photo: Missy Duncan in Wellsburg


Photo: Taylor Fevold – near Gladbrook

Photo: Meteorologist Denice Pelster near Grundy Center


Posted under Optics, Photo

This post was written by Kyle Kiel on May 27, 2017

Sun Halo

If you looked up at all during the early part of the afternoon you probably saw a ring around the sun. The ring is called a halo. It is produced the sunlight refracting off ice crystals that make up the high thin clouds. These clouds come from areas of rain in Missouri.

Click here for more details on a halo.


Posted under Optics

This post was written by Schnack on May 3, 2017

ICYMI Nov 30 – Circumhorizon Arc/ Colder Days Ahead/ Snow Cover/ White Sands

Circumhorizon Arc

November is going to go down as the second warmest November on Record. Things might be changing as we head into December, the first month of Meteorological winter (Dec/Jan/Feb). Temperatures are might be colder than normal December 8-14.


Here is a look at the snow cover across the U.S. today compared to November 30, 2015.


The White Sands of New Mexico looks like snow. Click here for a more detailed look at the photo and why it looks that way.


Posted under Long Range Outlook, Optics, Winter Weather

This post was written by Schnack on November 30, 2016

ICYMI Oct 24 – World Record Temp/Hole Punch Clouds/Seymour

The world record high temperature of 134 degrees was set in Death Valley (Furnace Creek), CA on July 10, 1912 …but did it?


There has been research as to the validity of the report. Back in February of 2013, there was a paper published showing, what was through to be the world record (136° in northern Libya), the reason why that record was no longer a valid record.

This would now make the 134° report at Death Valley the world record. Well…not so fast. Click here and take a look at some research that has been done on that temperature reading just posted. As of now 134° is the record. We will wait and hear from the World Meteorological Organization (WMO) says about it.


Hole Punch Clouds and Sundog


Hurricane Seymour (Cat 2 storms) is in the eastern Pacific Ocean Monday afternoon and forecast to strengthen. At this point the forecast keeps it away from land.




Posted under Clouds, Optics, Photo, Records, Tropics

This post was written by Schnack on October 24, 2016

ICYMI Sept 19…Antisolar Rays & Belt of Venus /90° Days/Baseball Sized Hail

Severe storms were in the forecast for this afternoon and evening, but little to nothing materialized. The reason for that is because of what is called a CAP. This is small layer of the atmosphere that is warmer and it prevented the air from rising quickly.


The high temperature today was 89 degrees in Cedar Rapids. I went back and looked to see how often does a high temperature of 90 degrees get reached in September at Cedar Rapids. Well, on this date is has done eight times. The chart below shows the calendar day at the bottom and temperature on the left. Each bar shows the number of days the temperature reached 90 or higher on that particular day. So again, on the 19th it was 90 or warmer 8 times on that day. Notice how fast the frequency drops off toward the end of the month…not very often.


Here is a look at how much rain has fallen so far this month across Iowa.


There is a great web page very interesting photos and descriptions of why things look the way they do. Les Cowley puts off of this information on the web page. There is a section called Optics Picture of the Day. I learn something new every time I go the web page. The photo is just one example of some great photos on there. Here is the link.


On September 18, 2002 a storm producing baseball size hail with wind gusts to 70-80 mph in Jackson County. Click here for more details on this event.


Posted under Optics, Precipitation Totals, Severe Weather, Temperatures

This post was written by Schnack on September 19, 2016

Sundogs, Parhelia, Mock Suns

Click here to see how these form.


Posted under Optics

This post was written by Schnack on January 7, 2015