How Hot Does a Road Flare Get?

by Alex Wittle

Road flares are useful emergency tools, especially for roadside safety and signaling. When lit, they can get extremely hot. But how hot do they really get? 


Credit: Envato Elements/ drazenphoto

 

What Is a Road Flare?

A road flare, a safety flare, or an emergency flare is a type of pyrotechnic device. It burns with a bright flame to signal distress, mark a location, or alert others to danger. Most commonly, they’re used on roads to warn drivers about a breakdown, accident, or hazard.

There are two main types of flares:

  • Traditional flame flares (these are burning flares made with chemicals)

  • LED flares (these are battery-powered and reusable)

How Hot Do Road Flares Get?

A typical road flare burns at temperatures between 1,400°F and 2,200°F (760°C to 1,200°C).

Here’s a breakdown:

  • Average burn temperature: Around 1,600°F (870°C)

  • Peak temperature: Can reach 2,200°F (1,200°C) depending on the flare size and composition

That’s hot enough to melt aluminum (melting point is 1,220°F). It can even cause severe burns on contact

What Makes Them Burn So Hot?

Most flares use a mix of strontium nitrate, potassium perchlorate, and magnesium or other metal fuels. The heat comes from the chemical reaction that occurs inside the flare when the metal and fuel react during ignition.

Why Does the Temperature Matter?

The temperature matters because it can cause a serious risk to safety:

There’s a risk of fire

Road flares can burn at temperatures over 1,400°F. That’s hot enough to ignite dry grass, clothing, cardboard, paper, or anything flammable nearby. If you're not careful about where you place a flare, it can easily start a fire.


You could seriously get burned

Touching the burning end of a flare, even briefly, can cause third-degree burns. Always wear gloves if you need to move or handle one, and never try to pick it up while it’s still burning or hot.


Vehicle safety and surface damage

If you drop a flare too close to your car, it could damage the paint, melt plastic trim, or even affect your tires. Always place flares a safe distance from your vehicle and avoid setting them directly on the road surface if possible, especially if it's hot asphalt or something flammable nearby.


How to Handle Road Flares Safely

Because of how hot they get, flares need to be handled with caution. Here’s how to use them safely:


Step 1: Read the Instructions

Before using a flare, read the label. Every manufacturer includes safety guidelines and ignition instructions.


Step 2: Wear Gloves

Use gloves if possible. Flares get hot even near the base, and gloves give you a bit of extra protection.


Step 3: Light Away from Your Body

Hold the flare at arm’s length. Point the igniting end away from yourself, others, and anything flammable.


Step 4: Place on a Safe Surface

Once lit, place the flare on:

  • Concrete

  • Gravel

  • Dirt

  • Metal stands (if available)

Avoid placing it on grass, paper, plastic, or inside your vehicle.


Step 5: Keep a Safe Distance

Once placed, step back at least 5–10 feet. Keep others away, especially children or pets.


How long do road flares burn?

Most standard road flares burn for 15 to 30 minutes, but some heavy-duty ones can go up to 60 minutes.


Can a road flare melt metal?

Yes, some road flares burn hot enough to melt certain types of metal, like aluminum which melts at 1,220°F, and lead which melts at 621°F

They won’t melt stronger metals like steel, which needs over 2,500°F to liquefy. They can still warp or damage it.


What to do after the flare burns out?

Once a flare is done burning, the danger isn’t over. The casing and leftover material stay hot for several minutes.

Here’s how to deal with it:

  • Give it at least 15 minutes to cool

  • Don’t touch with bare hands

  • Dispose of properly according to local hazardous waste rules

Never throw a used flare in regular trash while it's still hot. It can cause a fire.


Do LED Flares Get Hot?

No. LED flares are battery-powered and don’t use any heat or fire. They’re a safer alternative, especially in areas where fire risk is high.

Final Thoughts

A road flare is a powerful tool, but it comes with real safety risks because of how hot it gets. Use it properly, and keep it away from anything that can burn. 

Need high-quality flares for your car, truck, or roadside kit? Emergency USA flare kits come with everything you need for visibility and safety in an emergency. Shop with us today.

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