How Much Water to Bring on a Hike

By: Ashley Vitiello | Last Updated on May 2, 2024

For average hikes in moderate weather, you should plan on drinking at least 1/2 liter of water for every hour of activity. This number can increase dramatically based on a number of factors, so continue reading to get a better idea of how much water you need on your next adventure.

Water is an indispensable companion for every hiker. Keeping yourself hydrated ensures your body performs optimally, allowing you to enjoy every step of your journey while maintaining safety. However, determining exactly how much water to bring on a hike can often be puzzling. With factors such as the duration and intensity of the hike, weather conditions, and individual needs to consider, it can seem like a complex calculation.

We’ve designed this article to help you navigate through these complexities. By the end, you will have a clear understanding of how to assess your hydration needs before setting foot on the trail. Join us as we quench your thirst for knowledge and help you to never run dry on your hiking adventures again.

How Much Water To Drink While Hiking

As a general guideline, it’s recommended you drink about one liter (32 ounces) of water for every two hours of moderate activity in moderate temperatures. This rule can vary depending on factors such as weather, the intensity of the hike, and your body’s specific needs. However, it serves as a good starting point for estimating your hydration needs during a hike.

This quantity may increase in more challenging conditions. For example, in hot weather or during high-intensity hikes, your body can lose up to a liter or more of water per hour through perspiration. In these circumstances, it’s essential to increase your water intake accordingly.

If you carry a water filtration device or some type of water purifier, you can also filter water along the way, so you don’t have to pack all the water you need. This is especially nice on longer hikes and multi-day backpacking trips, where it may not be logical to carry that amount of water in one go.

It’s also important to remember that everyone’s body is different, and what works for one person might not necessarily work for another. Listening to your body’s signals of thirst and learning to gauge your own hydration needs is a crucial skill for any hiker. Keep in mind that feeling thirsty is already a sign of early dehydration, so aim to drink regularly, not just when you’re thirsty.

Hike TimeModerate ConditionsHot Conditions
1 hour0.5 liter1+ liters
2 hours1 liter2+ liters
3 hours1.5 liters3+ liters
4 hours2 liters4+ liters
5 hours2.5 liters5+ liters
6 hours3 liters6+ liters
A table illustrating how much water your should bring in moderate and hot conditions depending on your estimated hiking time.

Factors Affecting Water Intake

Several key factors affect how much water you need to consume during a hike:

  • Temperature and Humidity: These are probably the most critical factors. In hot, humid weather, you sweat more and therefore require more water. In cold weather, the body’s energy expenditure increases, and even though you might not sweat as much, you still need to keep hydrated.
  • Intensity and Duration: The harder and longer you hike, the more water your body will require. Strenuous activity like uphill hiking or hiking with a heavy backpack will increase your body’s water demand.
  • Altitude: At higher elevations, the body tends to lose more water through increased respiration. Consequently, you’ll need more water if you’re hiking in mountainous regions.
  • Individual Physiology: Everybody is unique. Factors like your age, body weight, sex, and overall health can influence how much water you need. Generally, larger people and those in better physical condition require more water.
  • Acclimatization: If you’re accustomed to physical activity and the environment you’re hiking in, you may need less water than someone who isn’t. Your body becomes more efficient at managing water loss as it gets used to exertion and climatic conditions.
  • Diet: If your meals are high in water content, such as fresh fruits and vegetables, you may require slightly less water. Conversely, salty or dehydrated foods can make you thirstier.

Hydration in Different Weather Conditions

Regardless of the weather, proper hydration is crucial during a hike. Adjust your water intake based on the temperature and humidity levels:

How Much to Increase Water Intake in Hot Weather

In hot weather, a good rule of thumb is to increase your consumption by approximately half a liter to one liter per hour compared to moderate conditions because your body can lose a significant amount of water through increased perspiration, potentially leading to dehydration. So if you are following the general rule of 0.5 liter per hour, you should increase to 1 liter or even 1.5 liters per hour depending on the conditions.

While it’s difficult to provide an exact amount of additional water intake required in hot weather, as this can vary considerably based on individual physiology and intensity of exercise, this is a good starting point.

Additionally, if you’re hiking for an extended period in hot weather, you should consider replenishing your electrolytes. Electrolytes help regulate your body’s fluid balance and are also lost when you sweat. Therefore, consuming sports drinks or specialized electrolyte replacements, alongside your increased water intake, can be beneficial.

water on a hike
The dry and hot climate in Utah requires lots more water than other places in the United States. Luckily this hike was short!

A recent study showed that while hikers usually bring enough water for hiking in hot conditions, only 23% of them consumed enough fluid to make up for the sweat they lost. This lead to heat stress that negatively affected the hikers’ performance measures. So remember that it’s not just about bringing the right amount of water, but it’s about drinking enough as well.

As mentioned before, the need for water can vary widely between individuals and situations. Always consider your personal needs and factors such as the intensity of the hike and the specific temperature and humidity conditions. Read more about tips for hiking in hot weather.

How Does Cold Weather Affect Water Intake

When hiking in cold weather, you should follow the same rule of thumb as above for moderate activity in moderate conditions, which is about 0.5 liter for every hour of hiking. The deceptive aspect of hiking in cold weather is that you might not feel as thirsty as you would when hiking in warmer conditions, and this can lead to unintentional dehydration. Therefore, it’s just as crucial to stay properly hydrated when hiking in cold weather as it is in hot weather.

Contrary to what some might think, hiking in cold weather can actually increase your body’s need for water. There are a few reasons for this. First, the air at colder temperatures, particularly in winter, is often drier, which can increase the rate of water loss from your body through respiration. Second, your body has to work harder to maintain its core temperature in a cold environment, and this increased metabolic rate leads to more water loss. Third, wearing multiple layers of clothing can cause you to sweat, leading to further dehydration.

Also, remember that your water source can freeze in cold temperatures, so you might need to take steps to prevent this, such as using an insulated water bottle or hydration bladders, and occasionally drinking water from them to keep it from freezing. Avoid drinking cold water and instead bring along warm liquids to help keep you warmer. Read more tips for hiking in cold weather.

The Importance of Proper Hydration

Maintaining proper hydration while hiking is paramount for your health, safety, and overall enjoyment of the experience. It fuels your body, helping your muscles, heart, and other organs to function optimally.

When you are well-hydrated, your body can effectively regulate temperature through perspiration, ensuring that you don’t overheat during strenuous uphill climbs or in hot weather. Adequate hydration also aids in digestion and nutrient absorption, keeping your energy levels sustained throughout your adventure.

However, the benefits of hydration extend beyond physical well-being. Dehydration can significantly affect your cognitive abilities, leading to dizziness, confusion, and impaired judgment — all of which can be particularly dangerous in the wilderness where prompt and sound decision-making is vital.

Additionally, hiking should be an enjoyable experience, a chance to connect with nature and challenge oneself. The discomfort of thirst, fatigue, or heat exhaustion associated with dehydration can quickly transform a delightful trek into a grueling ordeal. Therefore, understanding how much water to bring on a hike and maintaining good hydration habits is an essential part of your hiking preparation.

How to Plan Your Water Supply

Before setting off on a hike, it’s essential to estimate your water needs and plan how you’ll carry water for your supply. Consider the following steps:

Step 1: Estimate Hiking Duration

Determine the total distance of your hike and calculate how long it will take you to complete it based on your average hiking speed. Use our hiking time calculator to get an idea for how long you’ll be on the trail.

Step 2: Calculate Water Intake per Hour

Using the general rule of one liter every two hours, calculate your water needs based on your estimated hiking duration. For example, if your hike will take five hours, you’ll need at least 2.5 liters of water per person.

Step 3: Consider Weather and Physical Exertion

Adjust your water intake based on weather conditions and the level of physical exertion required for your hike. In hot or humid conditions or during strenuous hikes, increase your water supply accordingly.

Step 4: Account for Personal Hydration Needs

If you know you generally consume more or less water than the average person, adjust your water supply to suit your individual needs.

Step 5: Plan for Refills

If your hike includes reliable water sources, such as streams or lakes, plan your water supply based on the availability of these sources. Bring a water filter or purifier to ensure the water is safe to drink – read more on how to filter water in the backcountry.

hiking water
You won’t find any of these out on the trail, but there could be a beautiful stream that would allow you to filter some fresh water to enjoy!

Carrying Your Water Supply

There are various options for carrying water during a hike, each with its own advantages and disadvantages:

  • Hydration packs: Convenient for sipping on the go, but harder to gauge water levels. Opt for a 3-liter hydration pack for long day hikes. This is our preferred method since the easier access encourages you to drink water more frequently. Just make sure you regularly clean your water bladder with a cleaning kit.
  • Water bottles: A water bottle can be easier for monitoring water intake since you’ll see the bottle every time. Choose a BPA-free hiking water bottle with secure lids to prevent leaks. Good option for beginners who haven’t invested in all the hiking gear and they are also easier to clean.
  • Collapsible water containers: Lightweight and space-saving, but may be less durable and harder to access during hikes. These frequently have a built in filtration system, which can be ideal for filtering water while hiking.

Staying Hydrated on the Trail

Follow these tips to ensure you stay properly hydrated during your hike:

  1. Hydrate Before Hiking: Drinking 12-16 ounces of water before starting your hike to create a hydration “buffer.” This pre-loads your system and helps keep your pack lighter from water you would have had to carry.
  2. Sip Regularly: Take small sips of water every 20-30 minutes, rather than chugging large amounts at once.
  3. Monitor Your Body’s Signals: Pay attention to signs of dehydration, such as dark urine, headaches, or fatigue. Adjust your water intake accordingly.
  4. Optimize Your Gear: Choose breathable, moisture-wicking clothing to help reduce sweat and maintain hydration levels.
  5. Replenish Electrolytes: Consider carrying an electrolyte replacement drink (or tablets or gels) to help replace lost minerals and improve hydration efficiency.

Refilling Water Sources

If you need to refill your water supply during a hike, consider the following tips:

  • Choose reliable water sources: Check maps and guides for information on water sources along the trail.
  • Filter or purify water: Use a water filter, purifier, or chemical treatment to ensure the water is safe to drink.
  • Plan your refill points: Calculate how much water you’ll need between refill locations and adjust your supply accordingly.
how much water to bring on a hike
When collecting water, try to find clean water that’s flowing, like this alpine stream at Ice Lake.


Symptoms of Dehydration

Dehydration can manifest in several ways, including:

  • Headaches, lightheadedness, and fatigue
  • Feel Thirsty
  • Dark and strong-smelling urine
  • Irritability
  • Disorientation
  • Poor coordination
  • Stumbling and mumbling

While these symptoms might be mild inconveniences at home, they can become serious problems when hiking in remote areas. In severe cases, dehydration can lead to heatstroke and other life-threatening conditions.

To avoid dehydration, follow these guidelines:

  • Start hydrated: Drink plenty of water before setting off on your hike.
  • Take breaks: Pause for a few minutes every hour to sip water and rest.
  • Monitor symptoms: Pay attention to signs of dehydration and adjust your water intake accordingly.

Treating Dehydration on the Trail

If you experience symptoms of dehydration during your hike, take the following steps:

  • Stop hiking and find shade.
  • Sit down and rest.
  • Rehydrate with water, electrolytes, or sports drinks.
  • Cool down by soaking clothing or a hat in water.
  • Resume hiking only after symptoms have subsided or seek help if they don’t subside.

Final Thoughts

Embarking on a hike is an exhilarating experience, a chance to immerse in nature’s embrace and challenge your physical limits. But it’s crucial not to underestimate the importance of proper hydration. Understanding your body’s water requirements, accounting for individual factors, the intensity of the hike, and the environmental conditions are all key to ensuring a safe and enjoyable adventure.

So, whether you’re heading out on a leisurely trail or tackling a challenging mountain ascent, remember to make water your trusted companion. Stay hydrated, stay safe, and let the beauty of nature fuel your journey!

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About The Author

Ashley is an adventurous soul who loves all things nature, especially warm sunshine, wildflowers, scenic snacking, and mushrooms. She is an avid outdoor enthusiast who has spent years enjoying time outside doing things like hiking, camping, and rock climbing.
Her goal with Know Nothing Nomads is to make these hobbies easily accessible through knowledgeable content and how-to's based on all the stuff she's learned on her journey. If she isn't writing an article, she's probably in a forest looking at big mountain views and tiny pieces of moss on the side of the trail.

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