Clothes for Hiking IRNP

Isle Royale Average High and Low Temperatures, and Daylight Hours

Clothing you bring to hike Isle Royale National Park needs to meet the diverse conditions on the island, including preparing for variations by season and terrain. We also talk about optional clothing items, bathing suits, for example, or a towel, and some style choice differences. Our Garb course addresses all aspects of clothing in a lot more depth, so do check it out here. You will be prompted to create a login to check it out. The courses are free.

We put clothing choices in a perspective that keeps overall pack weight in mind while addressing weather. As we expressed in Backpacks, Gear and Weight Course everything you put in your pack effects its total weight, and ends up on your back.

Check the Forecast

Now even though the long term average for September is high 63 degrees and low 50 degrees Fahrenheit, this is only average. On our September 2020 trip, we experienced highs in the mid 50s and nighttime lows in the mid 20s. The averages can be a guide, but look to actual current forecasts for Grand Portage, MN , Thunder Bay, Canada and Copper Harbor, MI. for a little more idea to what you may encounter weather wise. Many people we know who go in late May/ early June, talk of finding snow and ice left from the previous winter.

Clothing is weather specific

There are several weather forecast locations that I find to be good for giving you a basic idea of what to expect for your adventure. They are Grand Portage, MN, Copper Harbor, MI and Thunder Bay, Canada. Just prior to departure, I look at the past week and the future forecasts and take the worst/coldest one and pack for that kind of weather.

KODAK Digital Still Camera
KODAK Digital Still Camera


Always bring rain gear. Even if it doesn’t rain, your rain gear is a great warmth-saving, wind-breaking, outerwear, worth it’s weight in your pack. Rain gear is not heavy at all. 

A complete change of dry clothes is essential for your safety. On Isle Royale, the temperatures can drop unexpectedly to the point where hypothermia is an issue. In an all-day, cold rain, a person can become completely soaked through. To protect from hypothermia, you must get dry and warm quickly.

If your budget does not allow for purchasing Dry Sacks, use gallon heavy duty freezer bags to ensure you maintain a complete set of dry clothes.

The same goes for your sleeping bag. Being able to get out of cold wet clothes, into dry clothes and a dry sleeping bag to warm up could be the difference between life and death in the backcountry of Isle Royale.

Heat–daytime highs

Temperatures can climb upper 80s on some of the ridges while hiking. This doesn’t mean it is the norm, but it happens frequently. Within our layers, though, we both have shorts.

Cold–nighttime lows

The coldest temperatures we have experienced were the third week of September 2020. Two nights consecutively (one in Feldtmann Lake and Siskiwit Bay)were in the mid 20s at night. Now we packed for this extreme and were well prepared with lightweight down backpacking  jackets and an extra base layer each. These items were in addition to our hats and gloves. 

Duane’s Minimum Clothing Items

All his clothing are synthetic or wool wick-away type fabric, including one pair of convertible pants, a long sleeve button up shirt, one tee-shirt, 3 pairs of underwear and 3 pairs of socks, These items fit into a 6 Liter Dry Sack and weigh 2 lbs. 10 oz. total including the bag.

On his person are a pair of socks and underwear, tee-shirt, long sleeve button up shirt and a pair of convertible pants. This allows for a change of clothes so that he can rinse a set and have them dry while wearing the other set.

Convertible pant
Raincoat, hat and gloves

He also takes a Black Diamond Stormline Stretch Rain Shell, a sock hat and gloves. They all pack into the jacket’s pocket and weigh 15 ounces. He also takes a synthetic base layer top & bottom, which weigh 11 oz.

He also brings a three-season down coat.

Beth’s Minimum Clothing Items

The Layering Idea

Like Duane, I layer my clothing, choosing season-specific layers to meet my needs. Remember, almost any month on Isle Royale can require at least a cool-weather coat and almost any month can also tempt one to take a bathing suit. 


Generally, I like midrise hiking boots, with which I will take three pairs of ankle-high (not knee-high) merino wool or wool-blend socks in addition to the pair I have on my feet. If the weather is cold or tends to dip down in temperatures in the evening, I will change out one pair of the ankle-high socks for calf-high ones to wear with pants or hiking tights. If it’s really cold, I will also take a silk sock liner to wear under the high socks if need be. 


I take a couple of sports bras and lightweight underwear. I can alternate bras, wearing one and washing the other. I pack 3 pairs of synthetic underwear.

Base Layer

I tend to feel colder than Duane; therefore, I need to have more layers than he uses. I take an under-base silk layer, both top and bottom, as well as a synthetic base layer top. I don’t take a bottom base layer in addition to the silk because I take long-legged hiking tights which double as a base layer under my hiking pants. 

Silk Base Layer top

The second base layer of silk is much lighter than any other, but it is not as warm as wool or synthetic. I take it as a second base layer to be worn under the synthetic for cold weather.

Notice that the silk base layer is so thin you can see through it. Nevertheless, it adds warmth that I need without the bulk and the weight under my firs base layer.


I take two tank tops and two roll-up sleeve, vented, water resistant hiking shirts in cold weather and only one in warmer weather. I wear one set for the crossing and one set is in my pack.

A new study led by the University of Washington has shown that mosquitoes have color preference. They seem to not be attracted to the color blue, so I wear blue. I don’t know if it makes a difference, but I am willing to give it a shot–anything to reduce the potential for being a target of mosquitoes.


I have found that zip-off leg, quick-dry hiking pants that work fine. The rolled-leg type collect debris, so I avoid them. In cold weather, I also take one pair of long-legged hiking tights because I find them more comfortable than the hiking pants. 

Capris Tights
Full-length Tights

The capris-length tights are my go-to choice in warm weather because they are comfortable. If it’s warmer, I take two pairs of capris and the convertible pants. If it’s going to be cool, I take one pair capris, one long-legged tights, and the convertible pants. 


I take two kinds of coats, a raincoat/windbreaker and an ultralight down jacket. If it is not getting colder than into the 60-degree range at night, which is very warm, I will only need the raincoat/windbreaker. If the weather promises to be in the 50-degree range, I will take the down coat and the raincoat, making sure that the raincoat will go over the down coat. 

Eveningwear on the Island

Hat & Gloves

I always take a knit hat and water-resistant gloves as well as a baseball cap. The knit hat can be for wearing in a cool evening as well as for sleeping if it is really cold. The baseball cap can be used to keep the sun out of my eyes. It also makes me less self-conscious about hair that isn’t washed as often as I’d like.  


The inland lakes will offer a nice way to rinse off. Even Lake Superior is a possibility, although it is frigid. If you have the body for it, choose the bikini–it weighs the least. If you want the one-piece, weigh your choices, literally weigh them. The fabrics that bathing suits are made of tend to be really heavy, so you may have to search to find one that works for you.  You can choose not to take a bathing suit and swim in your clothes, which also helps with getting things rinsed. 

Note: there are ribbon leaches in the inland lakes which may hitch a ride on you. They are not dangerous, and you can just pull them off if they get on you. Still, the more clothes you have on you in the water, the less skin is available for them to hitch a ride. 

Forget the towel. You don’t need the extra weight. The microfiber towels don’t dry anything, and terry towels are too heavy. If you must have something to dry with, take a hanky, which is very light, will help dry you off a bit, and it will dry quickly itself.

Cold Weather Adjustments

Notice that there is very little difference between warm weather and cold weather gear, which is because of the possible temperature extremes throughout the hiking season. Don’t bet that it won’t get cold or that it won’t rain. Plan that it will.

In cold weather, change out hiking gloves for more substantial ones. Consider taking hand warmers. Add a sleeping bag liner, and consider adding a down sleeping hood. Leave camp crocks home and use trail runners instead, or just stick with your hiking footwear and forego a camp shoe. It goes without saying that you won’t need the bathing suit.

Other necessities

Don’t forget sunblock if you are fair and bug dope (30% Deet for direct application; 100% Deet for clothing). You can opt for mosquito netting, but it is uncomfortable in the heat.

Note: Stable flies (the flies that bite on Isle Royale) are not deterred by insect repellent. You will need long sleeves and long pants to protect against them–if they are present, so don’t skip the convertible pants and long-sleeved shirt. Mosquitoes and stable flies can bite through most hiking tights.

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