How Hot Is Fire? The Complete Fire Color Cheat Sheet! - FFG

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About the Author: Hi! I'm Chris Hunt, a former firefighter from Orange County, California. After a work-related injury, I retired from the fire service. With 7+ years of hands-on experience and specialized knowledge of combustible materials, I have personally researched and compiled the information presented here.Please note that the content reflects my personal opinions and should not be considered professional advice. I do not guarantee the quality or performance of any products featured. Before using the site, please review the website’s Disclaimer and Terms and Conditions.As an Amazon Associate I earn from qualifying purchases (without additional cost or expense to you).

Table of Contents

How hot is fire?
What is the temperature of a fire by color?
Why is fire hot?
Is Fire the Hottest Thing in the World?
Can fire have multiple colors at the same time?
Examples of heat sources
Examples of materials’ melting point temperatures
The complete fire color cheat sheet
In conclusion

How hot is fire? Is it just orange, red, and yellow? What do the different colors even mean? Let’s find out!

How hot is fire?

When we look into humanity’s history, fire was one of the first things to enable humankind to prosper. We use fire daily for multiple reasons, like cooking, manufacturing, or keeping us warm.

Depending on the fuel that allows the fire to burn and its intensity, it can turn to different colors. These colors can be:

Blue
Red
Black
Orange
White
Yellow
Violet
Green
Indigo

So, how hot is fire? It depends on the color and energy source. You may want to learn about the fire triangle to understand better the relationship between oxygen, fuel, and heat that creates a flame.

What is the temperature of a fire by color?

How hot is blue fire?

The blue fire is hot enough to melt iron ores and extract iron. When humans could create blue fire, the Iron Age began.

In general, natural gas stoves create a blue flame used for cooking. Propane flames are also blue but have yellow tips. In general, a blue flame combines gas and oxygen and shows when there’s efficient combustion (as in no waste).

A blue fire averages between 2,550 and 3,000 Fahrenheit (1,400 – 1,650 Celsius).

How hot is red fire?

Red fire is one of the most common colors and has one of the lowest temperature burnings of its peers.

A red fire can get to 1,470 Fahrenheit (ca. 799 °C).

How hot is black fire?

Black fire is a rare phenomenon when combining fire with salt water. It’s a fragile flame that barely has light, therefore the color. It is highly unusual and not conventionally considered fire. Therefore, a black fire temperature is negligible.

Someone once asked me how hot are black flames? In the context of conventional combustion, they don’t exist.

How hot is orange fire?

Burning everyday items produces orange fire. It’s one of the most common colors since it’s the color at which carbon burns. Most organic material on Earth is carbon-based. For example, wood, vegetation, oil, charcoal, etc.

When humans successfully created orange fire consistently, the Bronze Age began. That’s because orange fire is strong enough to melt gold and copper.

An orange fire can get to 2,000 Fahrenheit (ca. 1,093 °C).

How hot is white fire?

White fire burns high and can melt uranium, nickel, or cobalt. A common phrase is when some say something is “white-hot.” It refers to being superheated or scorching.

A white fire can get to 2,730 Fahrenheit (ca. 1,499 °C).

Wood show how hot is fire by colors

How hot is yellow fire?

Burning sugar cane, wood pulp, or sugar produces yellow fire. It’s the second most common color in nature.

A yellow fire can get to 2,200 Fahrenheit (ca. 1,204 °C).

How hot is violet fire?

Violet fire is the strongest and hottest of all the colors. It can melt almost anything. Therefore, factories, welders, and cutting operations are among the few who use them.

A violet fire can reach above 3,000 Fahrenheit (ca. 1,649 °C).

How hot is green fire?

Green Fire is a liar! You can never know at what temperature it is burning. The reason is that the green color is not due to temperature but to the fuel used for burning. One of the most common materials that produce this color is copper.

So, how hot are green flames? While it depends on the material if we are talking about copper, the temperature at which it emits a green flame can vary. However, a green flame temperature typically exceeds 1,832 degrees Fahrenheit (ca. 1,000 °C). Therefore, green fire temperature based on copper would be around that.

How hot is indigo fire?

Indigo fire burns on the full range of what a blue fire burns. A big difference is that indigo is far simpler to manage than blue, so ironworking and glass production typically prefer this flame color.

An indigo fire can get to 3,000 Fahrenheit (ca. 1,649 °C).

Why is fire hot?

Fire is hot because it releases more energy from heat needed to sustain itself during combustion. If you carefully approach an open flame, you can perceive the energy or heat it irradiates. Just remember, every fire is hot and, therefore, potentially dangerous! Regardless of the fuel type that it uses.

Is Fire the Hottest Thing in the World?

It’s an interesting question. There is a lot of debate over which object is the hottest – fire, liquid nitrogen, the Sun, or the stars.

Fire is not the hottest thing on Earth, even at its hottest possible temperature, around 6,100 Fahrenheit (ca. 3,371 °C).

The hottest recorded temperature on Earth was an experiment conducted at the Large Hadron Collider at CERN. Their experimentation produced a mind-boggling temperature of 9.9 trillion degrees Fahrenheit (5.5 trillion degrees Celsius). That’s about 366,000 times the temperature in our Sun’s core!

Can fire have multiple colors at the same time?

Absolutely! Take, for example, a typical fireplace. Depending on the firewood and the flames’ size, the region near the logs will burn almost white or yellowish. That is due to the extreme heat at the base.

As we move higher, the flames turn orange and red. But that’s because the temperature reduces as we escape the heat’s source.

Huge Bonfire

Examples of heat sources

Candles: The outer core can typically burn at 1,400 degrees Celsius, while the inner body burns at 800 degrees Celsius. So, on average, a candle burns between 1,112-2,552 Fahrenheit (600-1,400 Celsius)
Cigarettes: the burning tip can get to 950-1,150 Fahrenheit (510-621 Celsius)
Fireplace: The logs in the fireplace can reach up to 600 Celsius
Match: When a single match burns, the temperature averages between 1,112-1,472 Fahrenheit (600-800 Celsius)
Oven: An oven wall can get to 600 Celsius
Bonfire: A big bonfire with charcoal and wood can burn at 1,100 Celsius
Bunsen burner: The Bunsen burner is the device used in chemistry to heat things and can reach 1,100 Celsius
The Sun: Scientists calculate the Sun’s surface to be at 2,000,000 degrees Celsius. On the other hand, the Sun’s core can get to 15,000,000 Celsius.

Examples of materials’ melting point temperatures

Stainless Steel – 1,510 °C
Cast iron – 1,127 – 1,204 °C
Graphite – 3,730 °C
Copper – 1,084 °C
Gold (24 Carat) – 1,063 °C
Aluminum – 660 °C
Wrought iron – 1,482 – 1,593 °C
Brass (Red) – 1,000 °C
Brass (Yellow) – 930 °C

The complete fire color cheat sheet

Now that we’ve explored the different colors and their temperatures, the following resume can come in handy:

Blue: averages between 2,550 and 3,000 Fahrenheit (1,400 – 1,650 Celsius).
Red: can get to 1,470 Fahrenheit (ca. 799 °C).
Black: N/A. It’s due to the fuel’s material.
Orange: 2,000 Fahrenheit (ca. 1,093 °C).
White: 2,730 Fahrenheit (ca. 1,499 °C).
Yellow: max 2,200 Fahrenheit (ca. 1,204 °C).
Violet: above 3,000 Fahrenheit (ca. 1,649 °C).
Green: N/A. It’s due to the fuel’s material.
Indigo: max 3,000 Fahrenheit (ca. 1,649 °C).

In conclusion

The color of fire can tell us a lot about its temperature. It can be an excellent way to understand it. However, sometimes, as it happens with green or black fires, that color can be misleading.

Fire can have multiple colors depending on the proximity to the fire’s core and the current stage of the fire. I.e., it’s not the same if it’s growing or fully developed. Finally, the combustion efficiency and fuel type can influence the flame’s color.