Nemo Mayfly Osmo 2 Backpacking Tent Review
Updated:
Mar 02, 2026The Nemo Mayfly Osmo 2 ($450) is a solid choice for backpackers who want a durable yet lightweight tent that won’t break the bank. It’s heavy for a semi-freestanding tent at three-and-a-half pounds, but still undercuts most of the freestanding competition—and comes with perks like a thicker-than-average bathtub floor and a comparatively low price tag. Overall, the Mayfly strikes a nice balance for recreational backpackers who care about longevity, but there are weaknesses to its semi-freestanding design.
Interior Space
Weight & Packed Size
Weather Protection
Durability
Ease of Use
Sustainability
Design Type
Semi-freestanding
Packaged weight
3 lb. 8 oz.
Floor Area
27.9 sq. ft.
Floor dimensions
85 x 52/43 in.
Peak height
42 in.
Floor Fabric
68D polyester
Capacities
2, 3P
Pros
Cons
Nemo Mayfly Osmo 2
Editor's note: The Nemo Mayfly has been discontinued for the 2026 season. Nemo still offers its popular backpacking-oriented Dagger and Dragonfly, and ultralight enthusiasts can check out the Hornet or Hornet Elite. For all of this season's top models, see our guide to the Best Backpacking Tents.
With almost 28 square feet of space in a tapered floorplan (43 in. at the feet, 52 in. at the head), the Nemo Mayfly Osmo 2 tent can accommodate two regular-sized (20-in. wide) sleeping pads. The ridge pole and arching, pre-bent main pole significantly increase the tent’s height both at the head and throughout, allowing me to sit fully upright without my head hitting the ceiling. (I’m 5-foot-6 inches tall and could change a shirt without having to scrunch.) This design (along with the 42-inch peak height) makes the Mayfly feel larger on the interior than my Big Agnes Tiger Wall, which has a 39-inch peak height and doesn’t use a pre-bent pole.
I slept solo in the Nemo Mayfly Osmo 2 while on a backpacking trip with friends in Washington State’s Enchantments. While the tent provided ample space for one person, adding another would have been tight. The tent’s tapered floor plan also makes it inconvenient to sleep head-to-toe with a tentmate. And if you or your tentmate has a penchant for rectangular, wide-sized sleeping pads (which measure 25 in. across), this isn’t the tent for you—they’ll fit at the head, but will have to overlap at the foot. Overall, the Mayfly is manageable for two people traveling with lightweight sleeping gear, but certainly not as spacious as a trekking-pole shelter or an untapered tent like the REI Half Dome SL 2+.
Although Nemo classifies the Mayfly as a lightweight backpacking tent, it’s objectively hefty compared to other semi-freestanding designs. At 3 pounds 8 ounces, it weighs a pound (or more) heavier than Big Agnes’ Tiger Wall and Fly Creek and is even heavier than Big Agnes’ fully freestanding Copper Spur (3 lb.). That said, the extra ounces are put to good use, increasing durability and—when compared with the semi-freestanding models—slightly more interior space due to the extra headroom.
The Mayfly packs down to roughly 6.5 by 19.5 inches, which is larger than the Copper Spur (4.5 x 19.5 in.) and Tiger Wall (5 x 18 in.). Some will appreciate the way Nemo’s square-shaped stuff sack fits into their backpacking pack; those who routinely store their tent on the outside of their ultralight backpack might object. For my purposes, I easily fit the Mayfly into my 65-liter Osprey Ariel backpack, along with my other sleeping gear, layers, and four days' worth of food. For solo backpacking trips, most people will want something slightly lighter, but if you’re sharing the weight (the Divvy Cube stuff sack is built so that the poles and tent can be split up), the Mayfly is a good option.
I tested the Mayfly in a range of trying weather conditions, notably on early-summer trips in Washington State’s Glacier Peak Wilderness and its smaller Enchantment range. In all types of moisture, the Mayfly fared well thanks to its Osmo rainfly and 68-denier PU ripstop floor (note: this floor is much thicker than that of most competitors—for reference, the Big Agnes Tiger Wall’s floor is 15D). Nemo’s proprietary Osmo fabric uses a poly-nylon blend that the company claims has longer-lasting waterproofing than similar materials and stretches minimally when wet (one-third that of other nylon flys). In practice, I had nothing to complain about: While camping on snow, the bathtub floor valiantly kept moisture out, even without a ground cloth; when the skies unleashed high in the Enchantments’ “core zone,” the rainfly prevented any rain or moisture from entering the tent and was still taut in the morning.
However, the strong winds my group encountered while camping in the Enchantments revealed a significant weak point in the Mayfly’s performance. The rainfly attaches to the tent by inserting a pin into a slot at each corner and then twisting until the pin is perpendicular to the slot. Without wind, this system works well; but during the heavy winds I experienced, the pins came out of their slots several times throughout the night, which resulted in a detached (and very loud and flapping) rainfly. I also noticed that the rainfly’s cord locks loosened in the wind, likely contributing to the pin-and-slot attachments coming undone. I wouldn’t wish this kind of sleepless night on anyone and would only recommend the Mayfly for lower-elevation and sheltered campsites.
The Mayfly features a 68-denier PU ripstop floor, which is much more substantial than most ultralight tent floors (the average is around 15 to 20D). The floor felt remarkably sturdy without a ground cloth (Nemo does offer a 70D footprint for $70), and I did not experience any abrasions or snagging when camped on granite and at forest campsites with pokey sticks and rocks. Similarly, the no-see-um mesh fabric on the tent body felt durable without being too heavy, and you get an average amount of nylon on the tent body (more than a mesh-heavy tent like the Big Agnes Fly Creek), which is arguably more long-lasting than mesh. Nemo does not provide a denier for the Osmo rainfly fabric as it’s made with two different fibers, but it felt significantly more robust than my Tiger Wall’s 15-denier rainfly.
Although the Nemo Mayfly 2P did not perform well in high winds, the lightweight aluminum poles exceeded my expectations. I’ve had carbon poles snap on me, so it was a relief to see that the aluminum poles barely bent in the strong gusts (I was happy to have the included repair splint just in case). Overall, the Mayfly is sturdier than most semi-freestanding tents, a key benefit of its heavier-than-average design.
I found the setup process for the Nemo Mayfly Osmo intuitive and easy to do on my own. The tent pitches with one main Y-shaped pole and a ridge pole, and mercifully has color-coded webbing and pole ends to serve as guides. The ends of the poles have metal balls (dubbed “Axial corner anchors”) that snap into place at the tent’s corners—a surprisingly satisfying experience. However, I noticed that snow or small pebbles tended to get into these sockets, which I then had to clean out to get the tent pole to snap in securely. The rainfly is anchored to the tent using a combination of a pin and a slot, which I detailed in the Weather Protection section above. My initial take on this hardware was that it was cool, innovative, and fun to use—but after a windy night that forced me out of my tent multiple times to reattach the fly, it lost its appeal.
Because the Mayfly is semi-freestanding, you have to stake out the two corners at the foot of the tent to be fully set up. Several guylines can also be staked out to create more stability in heavy winds. This does require good anchors, which were hard for me to find while camping on granite slabs and in the snow. I had to make deadmans (buried anchors in the snow) and scavenge for small boulders, making the setup process long and onerous. This is one of the primary downsides of a semi-freestanding backpacking tent; as a result, I’d recommend the Mayfly for those who stick to campsites with good ground anchors (read: dirt), but it’s not a great pairing for hikers who frequent above-treeline areas where they’ll be camping on rock and snow.
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Longevity
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PFAS-Free DWR
Durable water-repellent (DWR) finishes can contain PFAS (per- and polyfluoroalkyl substances). These highly persistent “forever chemicals” are used in outdoor gear for their strong resistance to water, oil, and heat, but are linked to environmental contamination and a range of health concerns. A green check mark indicates the product uses a PFAS-free DWR, while a red X means the DWR contains PFAS.
Recycled Materials
Recycled materials are prevalent in outdoor gear, with nylon, polyester, wool, and down among the most common, but the composition varies widely. A green check mark indicates the product is made with a substantial amount of recycled materials (100% recycled or the core fabric that makes up most of the product is recycled), a yellow check means it contains a moderate to small amount of recycled materials, while a red X means there are no recycled materials in the product.
Bluesign Approved
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Solution-Dyed Materials
Solution dyeing adds pigment to synthetic fibers during production rather than afterward, reducing water use, energy consumption, greenhouse gas emissions, and chemical waste, while also creating fabrics that resist fading better over time. A green check mark indicates a product features a substantial amount of solution-dyed materials, a yellow check mark indicates moderate or limited use of solution-dyed fabrics, and a red X indicates there are no solution-dyed materials in the product.
Responsible Manufacturing
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Recycled and/or Reduced Packaging
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Repair Services
Repair services extend the lifespan of outdoor gear and reduce overall consumption, though programs vary widely. Some brands offer comprehensive repairs for a range of issues, while others provide limited or no repair support. A green check mark indicates a robust repair program, a yellow check mark indicates limited repair services, and a red X indicates the brand does not offer repair services.
Resale and/or Recycling Services
Resale and recycling programs help keep outdoor gear in circulation longer and out of landfills, ranging from trade-in resale platforms that offer store credit to take-back initiatives that recycle products at the end of their usable life. A green check mark indicates a brand offers both resale and recycling programs, a yellow check mark indicates it offers one or the two, and a red X indicates it offers neither.
Carbon Footprint Tracking
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Annual Impact Report
Annual impact reports provide transparency and accountability by outlining a brand’s sustainability efforts across areas such as material sourcing, greenhouse gas emissions, waste, water use, supply chains, and packaging. A green check mark indicates a brand publishes a detailed, brand-specific impact report that closely aligns with our sustainability criteria and leaves little room for ambiguity. A yellow check indicates a brand provides some relevant sustainability reporting but lacks detail in key areas or is covered only briefly within a parent company report. A red X indicates a brand does not regularly publish an impact report.
With its double-wall design, the mesh body of the Nemo Mayfly 2P allows for great ventilation and moisture control. Nemo also included a strut vent above each vestibule door to prop open to increase airflow. On a clear night, the rainfly can be tied back on each vestibule door. Unlike some other tents I’ve used, Nemo designed the Mayfly with non-mesh fabric on the door, which offers slightly more privacy but slightly reduces ventilation. I’ve noticed no ventilation issues while sleeping solo in the tent; while sharing it with my climbing partner at the Glacier Peak basecamp, propping open the vents seemed to do the trick.
Interior Storage
The Mayfly includes one very generously sized pocket overhead that can hold large items—I used it to store my base layer, Kindle, and a couple of other small items. There is also a smaller rectangular pocket on the wall behind that head, where I kept my phone and charger a bit closer in reach. The Mayfly also features a pair of Nemo’s unique nightlight pockets, made from orange material to absorb the light from a headlamp and create a nice ambient glow. Though I appreciated the large pockets, I wish the Mayfly had pockets closer to the bathtub floor for easier access without having to sit up.
Vestibules
The Mayfly’s two vestibules (7.1 sq. ft. each) accommodated my 65-liter backpack and hiking shoes. While my backpack was completely covered by the rainfly, it was a close fit—one rainy night, mud splashed under the fly and onto my pack. For comparison’s sake, these vestibules are slightly smaller than those of many competitors (including the Big Agnes Tiger Wall), which are generally about 8 square feet.
Nemo Dagger Osmo 2P ($600): Maximize Your Backcountry Comfort
The Nemo Dagger Osmo is a step up in comfort from the Mayfly, with the price tag to prove it. Unlike the Mayfly, the Dagger is a freestanding tent (the corners of the foot end are pole-supported rather than a single pole running down the spine of the Mayfly), which translates to more versatility in choosing a campsite and an overall more stable, roomy build. It also prioritizes comfort with a rectangular floorplan—significantly wider than the Mayfly at the foot—more headroom throughout, and roomy vestibules (11.4 sq. ft. each compared to the Mayfly’s 7.1 sq. ft.). Surprisingly, the Dagger is only 7 ounces heavier than the Mayfly thanks to a thinner fabric set. We think the Mayfly offers a better balance of durability and weight, but the Dagger is a great option for comfort-seeking backpackers who still want to travel relatively light. For a deeper dive, see our Nemo Dagger Osmo 2P review.
Big Agnes Copper Spur UL2 ($600): Better Space-to-Weight Ratio
Big Agnes’ Copper Spur is one of the most well-rounded backpacking tents ever made and thus is a great gold standard against which to compare the Mayfly. For 3 pounds (a half-pound lighter than the Mayfly), the Copper Spur features a freestanding design, which is more stable in high winds and won’t require you to hem and haw over your campsite—just set the tent up on rock, snow, or dirt, and it’ll stand on its own. The weight savings and freestanding design are enough to warrant the price bump, which will be worth it for backpackers wanting the top-shelf combination of space-to-weight. However, the Copper Spur’s thinner fabrics (15D and 20D) will require extra care. For more, read our review of the Big Agnes Copper Spur UL2.
While the Mayfly ranks a tad below Nemo and other brands’ premium ultralight offerings, this tent still has much to offer. It’s durable, competitively priced, exceptionally waterproof, and light enough for most backpacking trips. However, it performs poorly in wind and doesn’t offer a good space-to-weight ratio.
Interior Space
Weight & Packed Size
Weather Protection
Durability
Ease of Use
Sustainability
The Nemo Dagger is made for hikers who want to max out backcountry comfort. The tent doesn’t levy too harsh of a weight tax, considering the room it provides, and it’s a well-constructed model. Its high price tag would fit better on a lighter design, though.
Interior Space
Weight & Packed Size
Weather Protection
Durability
Ease of Use
Sustainability
Our favorite do-it-all backpacking tent, the Copper Spur offers exceptional livability and weatherproofing for a minimal weight and packed size. Yes, its price is hard to swallow, but this tent won’t let you down.
Interior Space
Weight & Packed Size
Weather Protection
Durability
Ease of Use
Sustainability
Is the Mayfly 2P for You?
The Nemo Mayfly 2P is a bit of a curious tent in terms of where it sits within the greater market. Its main calling card is that it’s more durable than most backpacking tents of similar weight, with a 68-denier floor (most 3-lb. tents run around 15D to 20D) and an Osmo fly that’s reliably waterproof and does not sag when wet like other forms of nylon. As a result, it makes an intriguing option for practical backpackers looking for a great combination of price, durability, and weight savings, as long as you know what you’re getting with the semi-freestanding design (it isn’t ideal in serious wind or on rocky terrain). There are certainly lighter tents with similar interior space, but for its price and longevity, the Mayfly has carved out a small niche for itself in a competitive market.
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