The Osprey Tempest 20 is a reasonably lightweight daypack with some great features for light day hikes and commuting. It's made of both 70D and 100D Mini Shadow Brick nylon, with a 420HD nylon packcloth bottom and weighs 26 ounces. It comes in two sizes: XS/S (13-17" torso length) and S/M (16-20" torso length), both of which have adjustable torso lengths.
Like the Tempest but need a bit more room for longer day hikes?
Check out the
Osprey Tempest 30. It has many of the same features that we loved in the smaller model, but with ten more liters of carrying capacity and a top lid. Need even more room for one or two-day backpacking trips? The
Osprey Tempest 40 will do the trick.
Performance Comparison

Heading out to hike the Adirondaks with the Tempest, a super versatile pack.
Photo: Cam McKenzie Ring
Comfort
This frameless pack has a pliable shape that conforms pretty well to the individual wearer. The BioStretch harness is thin but padded and full of breathable holes that keep it pretty comfortable in the heat. The AirScape back panel rides the line between comfort, support, and minimalism. It's reasonably breathable as well, which we appreciate on a summer bike commute. What we didn't like too much was how the back pushed in on us when the pack was full. This problem has always bugged us a little, and now that a few daypacks are using the suspended mesh back system that keeps the entire pack off your back, you get more airflow and nothing pushing into you.
The hip belt also toes the line of being minimally designed while retaining a fair amount of comfort. It's integrated into the back panel to provide a continuous wrap around your waist (no seams between the belt and the bag touching you). We also love how soft the whole harness and back panel of this bag are. They're quite pleasant to wear against your skin on a warm day and do a solid job of flexing with you as you move.

The fully wrap-around hip belt is soft and comfortable, while the AirScape back panel does an okay job of ventilating as long as you don't pack it too full.
Photo: Maggie Brandenburg
Versatility
There are a lot of great features on the Tempest that make this a super versatile bag for commuting or day hiking. It felt like every time we used it we noticed something new!
The main compartment has one small internal mesh pocket with a key clip for stowing your essentials, and there's a separate top pouch that's rather large for things that you'll want quick access to, like snacks or a light layer. Then there's an external mesh pouch for a rain or wind jacket. This pack has two water bottle pockets and an internal slot for a hydration bladder (with a hook to hang it). There's a small vertical pocket on the left shoulder strap that can hold your GPS unit and an elastic Stow-on-the-Go loop that easily holds sunglasses. It also features two hip belt pockets and our favorite commuter features: the helmet LidLock. This is our favorite feature on this pack, as it's a quick and easy way to secure a bike helmet without having it bang all over the place. You pull the plastic piece vertically through the slots in your helmet and then rotate it so that it lays flat on top. The bungee cord creates enough tension to hold it in place, with no flopping around. Genius!

Sunglasses are easily stowed and retrieved from this stretchy band.
Photo: Maggie Brandenburg
There's also Osprey's "Stow on the Go" attachment for trekking poles, which carries them between your shoulder strap and hip belt (not the most comfortable carrying method for long distances, but convenient if you need to navigate a boulder field or steep section of the trail). Finally, there's an ice axe loop with a bungee strap holder for the shaft, a bike light loop, and a whistle on the sternum strap clip. There's no rain cover, though, so if that's a priority for you, look to one of those packs instead.

The "Lidlock" helmet attachment is a clever feature. Is secures your bike helmet quickly and easily with no flopping around.
Photo: Catherine McKenzie
Weight
At 25.75 ounces, this is one of the lighter fully-featured packs that we tested and runs about in the middle of the group for sheer weight comparison (next to some of those minimalistic, ultralight, and packable options).
We tested the S/M size, which Osprey lists as being a full 2L larger than the XS/S size. In addition to the extra capacity, it's also likely a bit heavier. However, we only ordered one of these bags to test, so we didn't actually weigh the other size. This weight also doesn't include any extras like a rain cover or hydration bladder. Or, obviously, the things that you'll carry around with you on your adventures.

The Tempest rides pretty excellently along the line between being lightweight while still fully functional and exceptionally versatile.
Photo: Maggie Brandenburg
Ease of Use
Though in the past, we've had a hard time finding a good fit in this bag, the ability of the torso to adjust with a simple velcro attachment makes a world of difference. On its smallest setting, the Tempest 20 seems to run a bit small, but our testers were all able to find a fit that was comfortable for them. Our main tester has a 17" torso (at the far high end for the XS/S size of 13-17") and was very comfortable wearing the S/M. It has all the adjustments we've come to expect from a more technical daypack and does a great job evenly distributing weight for a comfortable and balanced carry, no matter what you've brought.
The main compartment zipper has the ability to zip quite far down the sides, making it easy to pack full and find what you need without pulling everything out. We do think it's a tad small for our preferences - we're much happier with a couple of extra liters - but it's still very usable. The exterior hydration pocket is simple to use and compatible with pretty much any hanging hydration bladder, not just Osprey's. One feature we wish was better is the front expandable pocket. It's very small compared to most other daypacks, and we prefer a little extra room to jam a whole puffy and snacks in there if we want. However, jamming a pocket in that location so full would probably make it difficult to use the LidLock clip, so perhaps keeping it small is best for this bag.

We love that the back panel is velcro adjustable, though it still runs just a bit on the small side.
Photo: Maggie Brandenburg
Durability
This pack earned a great score for durability. We didn't experience any issues with this pack during our field testing and couldn't find any durability complaints in online user reviews. It's made of a 70D x 100D Mini Shadow Brick nylon body and a 420HD nylon packcloth bottom.
We like that this pack has beefier nylon on the bottom, but compared to many others we tested, it's on the thin and light side. If you live in an area with lots of pokey plants and sharp rocks, like the desert southwest, you should consider a pack with thicker material than this one for longer-term durability. Osprey does have a great "All Mighty Guarantee" warranty that will replace or repair defects or broken parts, but that doesn't include "cosmetic wear and tear," meaning that if you get a bunch of holes in the material, you're probably out of luck, and/or will need to patch them yourself. But if your intended usage is more on the "average" side of activities, this pack is a pretty solid choice.

Another area where the Tempest successfully straddles the line between low weight and serious durability - in addition to Osprey's All Mighty Guarantee to fix anything, anytime, for no cost.
Photo: Maggie Brandenburg
Value
This bag is on the low end of average regarding the prices of packs we tested. It's far from the cheapest, but also nowhere near the most expensive. We think that it offers an exceptional level of versatility and usability and a good level of durability that makes it very worth what you'll pay.
Conclusion
There's a lot to like about our Best Buy award winner. The Osprey Tempest 20 is lightweight, comfortable, and has some great features. We love this pack for commuting in the city, thanks to the bike helmet attachment point and low-profile design. And it works great on day hikes as well!

This daypack worked well for a variety of uses, including commuting, sightseeing, and light day hiking.
Photo: Cam McKenzie Ring