Outdoor Research Helium Pants Review: A Packable Rain Shell for Your Legs

Introduction

Rain pants are the least glamorous part of a wet weather kit, and they are often the first thing left at home. The Outdoor Research Helium Pants make a decent case for carrying them anyway. They are the legwear half of the Helium line, cut from the same Pertex 2.5 layer Diamond Fuse material as the Helium jacket, and the 2020 version was rebuilt to be lighter and stronger than the generation before it.

The fabric is a 100 percent nylon 30D ripstop, seam sealed on the inside, and the pants use YKK zippers throughout. A men’s version and a women’s version are both offered in black, pewter, and coyote brown, in sizes from XS to XXL. A medium weighs 6.2 ounces, and retail is $120. That combination of low weight, a small packed size, and a proper waterproof build is what makes these worth a closer look.

Who the Outdoor Research Helium Pants Are For

These are for hikers, backpackers, and travelers who want a waterproof layer that takes up almost no room in a pack. They fold into their own back pocket and press down small enough to almost disappear in one hand, so keeping them stashed for a change in the weather costs you very little space. They also pair naturally with the Helium jacket, forming a complete two piece shell.

They are also a sensible option for warmer trips. Breathability here is better than most shells at this price, which means you can wear them in mild conditions and stay comfortable as long as your effort level stays reasonable. That flexibility is a large part of their appeal: one small item covers snow, rain, cold, and warm weather without forcing a compromise on pack weight.

Main Strengths

The headline strengths are straightforward. The Helium Pants behave like a proper waterproof shell, they hold up over months of use, and they stay comfortable in conditions where cheaper rain pants turn into a sweat trap.

Waterproofing and Breathability

In extended use across snow, rain, cold, and heat, these pants have not leaked. The interior is fully seam sealed, and the construction has held up without letting water through at the seams. Breathability is where they separate themselves from budget rain pants. Less expensive shells will leave you noticeably sweatier, while the Helium Pants stay comfortable at moderate effort. As with any shell, pushing hard enough will still produce sweat, and that is simply the nature of a waterproof layer.

The 2.5 layer Pertex build is what makes that balance possible. The 30D ripstop face keeps the weight low while giving the fabric a hand that feels more substantial than its 6.2 ounce medium size would suggest, so the pants read as a real piece of equipment rather than a disposable emergency layer.

Durability and Build Quality

There have been no rips, tears, or fabric failures, and no issues with threads or seams. That is what you would expect from Outdoor Research, and it is what you get here. The details are well thought out too. The hem is elastic and includes a drawcord so you can cinch it tight, and at the foot there is elastic, a snap, and a zipper that runs roughly a foot up the leg to make the pants easier to get on and off over boots. There is a single back pocket with a flap over the zipper, sized well enough for a wallet, and the pants stuff into that pocket for storage.

Things to Consider Before Buying

There is no side pocket on these pants, which is the most noticeable limitation. Without a side zip, reaching your own pockets means pulling the pants down. That is not difficult, but in heavy rain it exposes you more than most people would like. A side zip that allowed pocket access would have been a significant improvement.

The same design logic applies to the front: there is no fly zip and no pocket zippers at all, which keeps the weight and complexity down but limits quick access. The other point to weigh is fit. These are cut as a slim fit, and some buyers may need to go up a size to be comfortable, particularly if they plan to wear them over insulated layers.

Sizing and Fit Notes

Because the cut is slim, sizing deserves a moment of thought before ordering. If you are between sizes, or if you usually layer bulky trousers underneath a shell, moving up a size is the safer choice. Both men’s and women’s versions are available across XS to XXL, and the three color options, black, pewter, and coyote brown, keep the look understated enough for town use as well as the trail.

Buying Advice

At $120 retail, these pants perform above their price range. The clearest evidence of that shows up in warm conditions, where the breathability advantage means you are not soaked from the inside after an hour of walking. The lifetime warranty from Outdoor Research is a meaningful part of the value as well: if something fails, the brand covers it, which is not something you get with cheaper alternatives that become your problem the moment you buy them.

If you already own the Helium jacket, these complete an excellent set and share the same fabric story. If you want quick pocket access without unzipping anything, the lack of side pockets is the trade-off to accept going in. For everyone else, this is an easy recommendation: super lightweight, durable, strongly built, properly waterproof, and comfortably breathable.

Conclusion

The Outdoor Research Helium Pants deliver what the Helium line promises in a small, packable package. The Pertex Diamond Fuse material is impressive in practice, the waterproofing and breathability are strong, and the construction has held up without complaint. The missing side pockets and slim fit are worth knowing about before you buy, but neither is a dealbreaker. Pair them with the Helium jacket and you have a complete shell that earns its place in the pack.