Can Guppies Live in Cold Water? No! Here is Why

Guppies are some of the most notorious tank fishes around the world. They are colorful, energetic, and cute and will bring a lot of color and life to your home.

That being said, guppies need specific living conditions to thrive and live their best lives. These conditions include proper lighting, adequate food, and fresh, warm water.

But can guppies survive colder waters? Many fish owners are interested in this aspect since many of them plan to keep the guppies outside. This guppy article will tell you everything you should to know about the guppies’ ideal living conditions.

Can Guppies Survive in Cold Water?

Guppies are tropical fish, which means they prefer warmer waters. The ideal temperature should revolve around 70 to 80 degrees F, which will ensure your guppies’ comfort and health. This isn’t to say that guppies don’t experience colder waters in their natural habitat, but the minimum temperature doesn’t generally go below 60 degrees F.

Below that, the guppies’ comfort will drop, and they will risk developing a variety of health problems.

Normally, you don’t need to worry about your aquarium water going below that temperature. The water will remain fairly warm, at room temperature, for an inside aquarium. The problem comes when moving the guppies outside, either in a pond or a specifically designed tank.

Can I Keep Guppies in an Outside Pond?

The answer depends on the area you’re living in. If you already live in a tropical area, you have few things to worry about. Your guppies will adapt quickly to the outside life since temperatures will always remain within the acceptable range. We are talking about a climate where the temperature never drops below 68-64 degrees F, even during the winter.

If you live in a more Mediterranean climate, things won’t go so smooth. The temperatures will be more than fitting during the warm seasons, like spring, summer, and part of the autumn. The winter, however, will see the temperatures dropping dramatically, well below the guppies’ survival threshold.

I recommend keeping the guppies at temperatures above 64 degrees F. Anything below that will start to affect the fish.

A Mediterranean climate is also manageable, albeit not ideal. During the warm seasons, the sun will warm the waters enough during the day to keep them acceptable during nighttime. This means you can keep your guppies outside day and night and only start worrying when autumn comes.

As soon as the temperatures begin dropping, I recommend taking your guppies inside and setting their habitat to the ideal temperature range. If your home isn’t warm enough for your guppies, you can always set a heater to make sure their water remains at optimal temperature.

Should I Use a Water Heater for my Guppies?

I would say yes, no matter the temperature in your home. The issue to consider here is that the room temperature can fluctuate pretty often. This can also influence the water temperature, and guppies don’t like temperature fluctuations since they affect their immune system.

Using a heater will allow you to monitor and control the water temperature a lot easier than relying on the overall room temperature. The heater will minimize the health risks coming with temperature fluctuations, improving your guppies’ comfort as a result.

How does Cold Water Affect Guppies?

As tropical fish, guppies rarely get to experience waters colder than 68 degrees F and, when they do, it’s usually for shorter periods. Coldwater will disrupt the guppies’ metabolism, causing a variety of health issues and behavioral changes along the way. These include:

– Affecting the Breeding Behavior

Guppies need excellent environmental conditions to breed successfully. These include the abundance of food, lack of predators, and the water temperature. Coldwater inhibits the guppies’ breeding behavior since the guppy knows instinctively that the fry can’t survive in that water.

Compared to adults, the fry needs even higher water temperatures, generally between 76 and 80 degrees F. These temperatures are ideal for promoting growth during the fry’s first weeks of life.

– Higher Risk of Disease

Cold waters will affect your guppies’ metabolism, causing them to go lethargic, stop eating, and fall sick. Eventually, they will start dying. As tropical fish, guppies can’t adapt to cold waters and will only withstand lower temperatures for short periods of time.

To prevent your guppies from developing potentially deadly health issues, I recommend keeping them in water temperatures similar to their natural habitat.

– Psychological Problems and Stress

Low water temperatures affect the guppies’ immune system and affects their physiological functioning. You will start seeing your guppies grow more irritable and aggressive as a result. They may start attacking other fish, resort to cannibalism, and show signs of lethargy and low levels of energy.

You can tell that your guppies are stressed by assessing their general behavior. Some of the most compelling signs include:

  • Erratic or sluggish swimming
  • Lack of appetite for extended periods of time
  • Seeking to hide behind rocks, plants, or other tank structures
  • Swimming at the surface longer than usual
  • Attacking other fish without no apparent reason
  • Not reacting when being attacked by other fish, etc.

You should take action as soon as you notice any of these erratic behaviors. If the water temperature isn’t the problem, maybe it’s water oxygenation. Whatever the cause may be, investigate and seek reliable solutions fast.

– Low Activity

Guppies are generally energetic fishes, constantly swimming, exploring their environment, and interacting with other fish. Seeing them lethargic, uninterested, and devoid of energy for longer periods of time is unnatural and should concern you. Guppies are cold-blooded creatures, just like snakes and alligators, for instance.

This means that they are most active in warm environments. Cold temperatures will cause them to go lethargic in an attempt to conserve their energy. If you don’t know your guppies to be sick but appear lethargic and less energetic than usual, verify the water temperature.

If the water temperature is fine, you should also check the water oxygenation or check your guppies for other signs that may suggest a health problem.

Which are the Best Cold-Water Fish?

If guppies aren’t an option for you or you simply want cold-water fish to keep outside, here are some options to consider:

– Goldfish

The goldfish is a staple in the fish-growing business. They are compatible with a lot of other aquarium fish, are beginner-friendly, and can grow quite large and beautiful. They also thrive in temperatures lower than those that guppies can withstand.

Depending on the goldfish strain, you can keep goldfish in temperatures ranging between 40 to 78 degrees F with different variations. Some types of goldfish will not enjoy waters colder than 68 degrees.

You should also remember that goldfish can produce a lot of waste. Cleaning the water regularly is a must, especially if you plan on keeping a lot of them in a pond.

– White Cloud Mountain Minnow

This species thrives at temperatures around 60 degrees F with small variations. They can’t handle temperatures above 72 degrees too well, which means they don’t make good aquarium buddies with guppies.

The Minnow is a small and colorful fish that will definitely spice up your aquarium. They are also friendly and peaceful, making them the ideal addition to community aquariums since they can make good friends with other fish.

– Pearl Danio

This is another aquarium fish that can adapt to colder temperatures with relative ease. They are generally shy and peaceful and thrive when paired with other fish of similar behavior.

– Gold Barb (Chinese Barb)

This gold-nugget fish is extremely popular among fish lovers for obvious reasons. It’s a handsome breed with a gold sparkle that enjoys flowing water. Having a powerhead in your aquarium will provide it with all the natural comfort it needs.

– Buenos Aires Tetra

This small and colorful fish is easy to come by, easy to care for, and tolerates 60 degrees and above temperatures. They enjoy the company of other fish since they are calm and friendly but tend to eat a lot of live plants.

You should keep that in mind if your aquarium is rich in live plants that you want to keep.

– Hillstream Loach

This fish isn’t necessarily adapted to cold waters but can tolerate them quite well. It is a bottom-dwelling breed with distinct gyroscopic eyes and a unique blue and yellow pattern. The fish will reach 3 inches in length and comes with spots and stripes, along with pectoral and pelvic fins.

It enjoys lurking in the aquarium bed, which means it poses no threat to other fish or vice-versa.

– Weather Loach

This eel-looking fish is another bottom-lurking specimen with an elongated body and a unique presence. The fish stands at 5 to 8 inches long and can easily withstand temperatures of 60 or even 55 °F. Some may even go lower than that.

The Weather Loach comes from East Asia, so it may not be easy to find in fish shops. It’s definitely worth searching, however.


Ideally, your guppies should remain inside in a heated aquarium. These are tropical fish familiarized with warmer temperatures. Cold waters will affect them, disrupting their mating and reproductive behavior, lowering their immunity, and making them prone to illness. Eventually, it will kill them.

You can move your guppies outside, but only if the weather in your region allows it. Remember, the water tends to be colder outside compared to inside due to the overall colder air. You should only keep your guppies in an outside pond if you live in a tropical area where temperatures are unlikely to drop to critical levels.

I also recommend getting a heater to make sure that the water temperature remains stable year-round.

avatar Noah
I’m Noah, chief editor at VIVO Pets and the proud owner of a playful, energetic husky (Max). I’ve been a volunteer at Rex Animal Rescue for over 2 years. I love learning and writing about different animals that can be kept as pets. read more...

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