Is a 30-Degree Sleeping Bag too Hot for the Summer?

Nobody expects to be perfectly comfortable when they go camping. However, making smart decisions with your gear can be the difference between a good night’s sleep and a night of tossing and turning. Understanding temperature ratings and what they mean can be a big first step in finding the right gear for your trip.

A 30-degree sleeping bag will usually be fine for the summer. Typically, only the hottest climates on the hottest days would make a 30-degree bag too hot. If you do feel too hot with a 30-degree sleeping bag, the bag can be unzipped and used as a blanket.

In this article, we’ll explore the question of sleeping bags in greater detail. Note: all of the temperatures in this article are in Fahrenheit

Understanding Temperature Ratings

The activity of “camping” has a wide range of participants. Some people consider themselves survivalists and work to make it through the night no matter what, while others would prefer the new phenomenon of glamping, where comfort is as important as the experience itself. Here, we seek to give you a solid understanding of sleeping bags so that you can find a bag that works not only for your survival but for your preferred comfort level as well.

The most important thing to understand about the temperature ratings on sleeping bags is that they are lower limits, meaning that you can survive at that temperature, not necessarily be comfortable. For example, a sleeping bag rated at 30º will keep you alive during the night when the temperature hits 30º, but you’ll probably still be cold and uncomfortable.

For this reason, it’s important to understand what kind of camping experience you want to have. If you’re a survivalist and don’t mind shivering through the night, then the extra weight of a heavier sleeping bag might not be worth it to you on a backpacking trip. If you’re a glamper, then going with a sleeping bag that will keep you not only alive but also warm is extremely important.

For comfort, it’s usually recommended that your sleeping bag be around 10º warmer than the low for the night. If the temperature will be 40º Fahrenheit, having a 20º or 30º sleeping bag should be enough to keep you comfortable.

However, keep in mind that temperatures can dip unexpectedly. As a general rule, we would plan for around 10 extra degrees as a buffer. In other words, if the forecast says 30, act like it will be 20 (that means for comfort, you’d pack like it would be 10). This should help ensure that you stay on the safe end of things and don’t risk getting hypothermia or having other cold-related problems.

Understanding Climate

To really understand what kind of sleeping bag will be necessary for comfort, it’s important to understand some of the nuances of climate and temperature differences as well. This is because small differences in numbers on paper can make big differences when you’re trying to fall asleep.

First of all, understanding temperature. We mentioned above that you should plan for temperature drops just in case the temperature fluctuates. Predictions of temperature can be sporadic and—frankly—unpredictable.

When considering comfort, the “actual” temperature and the “feels-like” temperature can be important too. For this reason, it can be important to consider factors such as wind-chill, cloudy weather, unexpected weather, etc. Remember, it’s always better to be overprepared than underprepared!

We won’t go into depth on all of these topics, but we will offer some important considerations.

Elevation

Elevation is one of the most important factors when considering what kind of sleeping bag you need relative to the temperature. The same night in the same place can be relatively warm at 4,000 feet but gets close to freezing at 9,000 feet. As someone who grew up hiking and camping in Utah, I can say that the mountains are colder than the cities—and colder than you’re expecting.

If you’re going to be camping at higher elevations, be ready for lower temperatures and even more extreme temperature drops. While a few places have temperature predictions for higher elevations, many temperature predictions do not happen for higher elevation mountains, especially if they are not popular. Be ready for lower temperatures than what is predicted.

Humidity

Humidity is another important factor to consider along with the temperature. We tend to associate humidity with stifling heat and biting cold, but dry summer nights can be dangerous in their own right. Keep in mind that desert temperatures can fluctuate from above 100º during the day to below freezing at night.

When considering humidity, keep in mind that all levels of humidity can be dangerous and may require different approaches. Whether you’re camping in humid or arid weather, having lots of water is important. Water is important not only for hydration but also for temperature regulation. If you’re dehydrated, you’re more likely to feel too hot or too cold.

While we won’t dive into a whole discussion on the humidity-temperature relationship, a good rule of thumb is that higher humidity equals hotter temperatures. While a 30-degree sleeping bag will usually be fine for summer temperatures, if you’re planning on camping somewhere that is both humid and hot, you may want to consider your temperature rating more carefully. Being cold isn’t comfortable, but neither is sweating up a storm and not being able to cool down! The key is to find the balance.

Understanding Personal Differences

Even after understanding ratings and climate, you may still find yourself wondering why you’re too hot or cold according to these guidelines. That’s the key: these are all generalized guidelines. These are meant to work reasonably well for the majority of people, but they are not one-size-fits-all. While personal differences can be varied and nuanced, here are a few tips that might be helpful:

Gender

Some sleeping bag ratings will change their temperature ratings based on gender. This occurs because women tend to be colder when they sleep than men. As a result, many companies drop their ratings on women’s bags by about ten degrees. This is normal, and nothing to be worried about, but it is good to be aware of the difference.

Muscle Mass

Another important factor to consider in your own personal temperature regulation is muscle mass. In general, people with a lower proportion of muscle mass relative to body surface area tend to be colder. According to this logic, the people with the least amount of body fat would be the coldest.

Circulation

Body circulation is important because it affects body temperature regulation through blood flow. If you have poor circulation, you’ll tend to feel cold more easily and more quickly, especially in your hands and legs. Keep in mind that what you wear and how tight your sleeping bag is can affect blood flow, especially in the legs.

Experimenting

In the end, you’ll probably have to experiment a little bit with some different bags, brands, and temperature ratings to find what suits you best. As you do this, keep in mind that safety is your most important priority; don’t try a sleeping bag that might not be warm enough unless you have a backup plan!

Some important things to consider:

• Your base layer can affect your temperature as well. A good base layer should consist of at least a loose-fitting top and bottom, with socks, a beanie, and possibly gloves as optional add-ons. Make sure it’s not so tight that it restricts blood flow.
• The size of your sleeping bag can affect your temperature level. Sleeping bags with extra space take longer to heat up. The best sleeping bag has enough space for you to be comfortable, but should not have so much extra space that it takes hours to feel warm.
• Your sleeping pad/tent can make a difference, especially your sleeping pad. Different materials/kinds/designs of sleeping pads can change the temperature, as can whether you’re sleeping in a tent, a hammock, a cot, or another sleeping arrangement. All of these are important to consider and try when experimenting to find what fits you best.

As always, remember safety first, and have fun camping!