One of the most important skill you can have in a variety of emergency situations and disasters is signaling. The ability to draw attention to you, dramatically increase visibility, or simply communicate over long distances is absolutely paramount in all kinds of scenarios. And one of the oldest, simplest and best signals is the humble flare.

Whether they are launched from a gun, handheld or fixed in place, all flares have a lifespan, and understanding the limitations of that lifespan will help you use them better. So, how long do flares burn?

Flares will burn anywhere from 45 seconds to 60 minutes depending on the size and type of the flare. Aerial flares have a much shorter burn time, while handheld and stationary flares tend to burn longer.

Most flares, whatever their chemical composition, function pretty much the same but they are designed for different environments and different methods of deployment and employment.

So you’ll need to be familiar with all of them, and especially know what you are dealing with when it comes to burn time if you want to make the most of them.

Keep reading and I’ll tell you everything you need to know about flares, their burn time and other relevant use factors.

How Long Do Traditional Flares Burn?

Traditional chemical or pyrotechnic flares have highly variable burn times. Flares that are fired from flare guns or other launchers (called aerial flares) usually have a burn time of about 45 seconds, sometimes as little as 20 seconds, in order to reduce the likelihood that they will start unintended secondary fires when they hit the ground.

However, flares of this type that have parachutes intended to keep them aloft for longer will almost always burn longer in kind to increase visibility over a greater duration.

Handheld flares, or flares that are designed to be placed on the ground or other holders, will have a typical burn time of anywhere from 10 minutes to an hour.

One great example is the common highway emergency flare, sometimes called by its old-fashioned name the fusee.

This varies from type to type and also from manufacturer to manufacturer, and the only way to know exactly how long a flare will burn is to consult any printed specifications on the body of the flare or the manufacturer’s packaging.

How Long Will Flares Burn in Wet Weather?

Damp conditions and rainy weather can affect the burn time of all flares. Although most chemical flares are at the very least water-resistant, not all flares are waterproof.

It is possible that enough water could put out certain kinds of pyrotechnic flare, whereas others, specifically those used in maritime environments, will often continue burning as they float on the surface of the water.

Generally speaking, for common signaling flares that are not wet weather optimized, damp conditions might cut burn time by as much as 50%.

Will Flares Burn Longer in Warm or Cold Weather?

Usually neither. Most emergency signaling flares designed for the purpose have a wide temperature range in which they will operate normally.

This means you should expect the prescribed burn time in hot or cold weather, so long as it is inside the manufacturer’s specifications.

Remember, it is moisture far more than temperature that is likely to affect the burn time of your flares.

But, if you wanted to get down to the nitty gritty, your flares will likely burn a little quicker and a little hotter in very hot environments compared to colds, although the difference is likely to be marginal.

How Long Can You Store Flares Last Before They Expire?

Flares don’t last forever, and even the best-manufactured emergency flares have a definite shelf life before they can be considered unreliable or even unsafe to use. Once again, this varies depending on the type of the flare and the manufacturer.

Common highway safety flares usually have a prescribed shelf life of around 3 years, and this is often specified as 3 years in normal conditions, meaning stuck in the trunk of your car while it is hot or cold outside.

However, some types have a lifespan of 6 years or even beyond before they are considered suspect.

In all cases, consult the printed instructions on the flare itself or the packaging it came in, and if you have any doubts contact the manufacturer of the flare if you are able for more information.

You should note also that just because a flare is past its specified shelf life that does not mean it won’t function normally, or that it is unsafe to use.

The point is that it might be, and you should plan according. I’ll tell you right now that any old or expired flares get replaced immediately in my personal vehicle, and I think you should do the same.

But at the end of the day, the only way you’ll know for sure whether those old flares will function is to actually try them.

Consider doing some testing with your expired or out-of-date flares so you might have a better idea of what you can expect from the next batch when they start to get old.

Do Storage Conditions Affect Flare Shelf Life?

Yes, absolutely. Like most things made from various chemicals, and pyrotechnics in particular, storage conditions play a huge part in the shelf life and functionality of flares.

Broadly speaking, your flares will work best and last longest if there are kept in a cooler room temperature environment in the dark.

Direct sunlight, extreme high or low temperatures and constant temperature shifts will degrade storage life somewhat, though you can typically rely on your manufacturer’s instructions to tell you what sort of typical storage conditions flares can tolerate.

Emergency flares of all kinds, be they railroad, highway or maritime, must be able to endure significant temperature variations and often rough handling for them to remain useful and ready to use when called upon.

They don’t need to be babied, per se, but you should take as good care of them as you can…

What’s the Best Way to Store Flares?

The best way to maximize flares’ “shelf life” is however the manufacturer tells you to store them. That’s no joke, they know best.

Generally speaking, most flares you purchase, whatever kind they are, will come with a case, bag or carrier that is also designed to protect them while they are in storage or transport.

That being said, you should always do the best you can to protect flares from moisture, even if they are maritime-grade flares.

If possible, store them in a securely latching waterproof case that will hold them securely in individually nested compartments or holders to prevent them from banging into each other and getting damaged.

Specifically, if you have a flare pistol or other launcher for aerial flares, always store them in the factory-designated case or container for safety.

Aerial flares have primers just like firearm cartridges that, if struck, may discharge and activate the flare with disastrous results!

How Should You Dispose of an Expired or Old Flare?

Old flares should be disposed of by any company or at any center that has the equipment and expertise to deal with hazardous materials.

You might even be able to get rid of them at your local city or county hazardous waste turn-in day or center.

Alternately, as long as conditions are safe to do so you can try to activate the flares so they can burn off safely under control conditions. Just make sure you have a backup plan in case something goes wrong.

Under no conditions should you ever just throw flares away in your usual garbage.

How Hot Do Flares Burn?

Most emergency signaling flares of any kind burn ferociously hot, around 2,600 °F (1426 °C).