Review: Nemo Equipment Mayfly Osmo 2-Person Tent

Nemo Equipment’s backpacking gear is not cheap, but it’s some of the lightest, best-made, and most well-thought-out gear you’ll find on the market. The company’s new Mayfly Osmo two-person backpacking tent exemplifies this. The Mayfly Osmo is quick to set up, lightweight, and cleverly designed, and it gave an impression of durability in my five nights of testing.

The Mayfly comes in two- and three-person versions and sits in Nemo’s backpacking tent line between the ultralight Dragonfly and Hornet series and the roomier, heavier Dagger series (8/10, WIRED Recommends). The Mayfly is a good choice for backpackers looking to pick up a quality Nemo tent that weighs a little more but at $400 costs quite a bit less than the ultralight Hornet.

The Basics

The Mayfly is a three-season backpacking tent with a trail weight of 3 pounds, 8 ounces for the two-person version I tested. Purists might take issue, but to me that puts it firmly in the ultralight tent category. Split between two people, each is carrying under 2 pounds. That’s not as light as the Nemo Hornet, which has a trail weight of just 2 pounds, but it’s well under our suggestion to keep tent weight under 2.5 pounds per person. The Mayfly is also $250 cheaper than the Hornet, making it easier on the pocketbook.

The Mayfly uses a semi-freestanding design, much like the MSR Freelite we reviewed last year. This design saves on weight since there are fewer poles, but it does mean you have to stake out or otherwise secure the foot-end of the tent. If you’re headed somewhere you might camp on hard rock, it’s worth adding some extra cord in case you need to get creative.

There are two tent poles, both aluminum. One is a hubbed three-piece pole that forks above the door. The second spreader pole goes across the middle and helps maintain the steep sidewalls that make the Mayfly surprisingly roomy for its dimensions.

The Mayfly offers 27.9 square feet of living space, with two 7-square-foot vestibule areas for gear storage. In practice, this works out to be a livable, though not roomy, tent for two. Since I happened to be testing Nemo’s new Tensor Trail sleeping pads as well, I can say that two of those fit side by side, but just barely (see photo). There’s a few inches of room down at the feet for gear, but whatever you put down there will be touching the sidewalls, which is often a recipe for wet gear.

At this weight, the Mayfly’s living space is about average. It’s nearly identical living space to the Big Agnes Tiger Wall UL 2, and it’s a couple square feet smaller than the MSR Freelite. I did not notice the difference much—the Mayfly feels bigger than the Freelite thanks to a wider roof, though it’s worth noting the Freelite is almost a pound lighter. The Mayfly is a good size for couples or anyone who doesn’t mind being a bit chummy with their partner. It was a perfect fit for me and my 9-year-old son.

Most of the Mayfly is a whitish mesh netting, but the roof is dark mesh to make the view better at night, and stargazing in the Mayfly is quite nice on those nights when you don't need the rainfly. There are two pockets on the ceiling, one above the head which is big enough for a Nalgene water bottle or other smaller items. There's a larger pocket toward the back where you can shove a couple of mid-layers to quickly grab on those chilly mornings. Night light pockets will diffuse your headlamp's LEDs to create a warmer, softer light.

The doors are quite large, and it was easy to get in and out of them, which was my main gripe about the Dagger, which is much harder to access. The floor of the Mayfly is made of 68D ripstop polyester and feels more substantial than others I’ve used. That said, I always recommend carrying a ground sheet of some kind, whether a piece of Tyvek you cut to shape or the Mayfly footprint Nemo sells for $70.

Setup and take-down are both super fast and easy. I was able to get the Mayfly up in under three minutes without reading the directions. Adding the fly, staking, and guying it out completely takes a bit longer, but the basic tent is very quick to set up. The poles snap into Nemo’s custom Axial corner anchors, and the color-coded webbing makes it simple to figure out which loops go to which pole.

The corner anchors deserve special mention, the snap-in pole loop is nice enough, but the clip-in rain fly anchors are genius. Because they attach both the pole and the rain fly to a single point, you can adjust the tension just by tightening or loosening a single strap. It’s the best tent-pitching system I’ve used.

As you would expect, Nemo gives you some stakes and guy lines, which get the job done, though I prefer MSR’s Carbon Core stakes—which are expensive, but they’re the strongest ultralight stakes I’ve tested. Nemo also includes a pole splint should you damage a pole on the trail.

Like the Dagger I reviewed last year, the Mayfly’s rainfly uses Nemo’s Osmo fabric. Osmo fabric is a nylon-polyester blend made with 100 percent recycled nylon and polyester yarns, woven so that it stretches less and repels water more than nylon alone. It’s also made without the use of flame-retardant chemicals or fluorinated water repellents (PFC and PFAS). Osmo is also now bluesign approved, which is a certification that ensures fabrics meet certain ecological and chemical requirements that lower their overall impact. After reading Alden Wicker’s To Dye For, I’ve become somewhat cynical about claims of this sort, but given how toxic many outdoor fabrics are, it’s nice to see Nemo making an effort in this direction.

In practice, Osmo does a good job of repelling rain, and as you can see from the photos, the rain fly does indeed stay nice and tight.

Overall the Mayfly is a very solid tent best suited for backpacking. You could use it in the front country as well, but if you’re just car camping you’d probably be better off with something cheaper, heavier, and roomier. If you like the Mayfly, it's worth noting that there is also a three-person version that offers a little more space. Within the realm of backpacking tents, the two-person Mayfly is a good entry-level option. It’s reasonably priced for what you get, and you get everything you need to hit the trail.