The temperatures are beginning to drop so most of us need a garment to keep us toasty - that's where down jackets come in.
Filled with either a thin layer of duck or goose feathers, the best down jackets on the market trap all the warm air from our bodies to help us combat the cold temperatures outdoors. They come in all different shapes, sizes and fabrics so if you'd like a little more information then check out down jackets buyer's guide for advice and tips for buying.
But for now, here are six of the top lightweight down jackets on the market with varying prices, weights and fabrics to give you an idea of what's out there.
Rab Microlight Jacket
A down jacket used as either a warm layer or weather-resistant stand-alone garment, the Rab Microlight is a light, versatile product of the British brand.
The jacket's big draw is the fact you can either wear it as a warm layer, if you're a climber like Libby Peters for instance, or a casual, everyday jacket to walk around town in - very typical of Rab's versatility.
The combination of the water-resistant Hydrophobic down and the breathable, windproof Pertex Microlight outer fabric makes the jacket very strong against the elements, while the fitted cut and low-key colour patterns mean it looks good as a lifestyle garment.
It is of course very lightweight too, at only 370 grams it is great to carry around as an extra layer in the hills and thanks to its minimal construction, it packs very small. Effectively, you're getting two jackets in one, so the price is very reasonable.
Mountain Equipment Arete Jacket
A down jacket with a bit of everything, Mountain Equipment's Arete is set out to be the 'perfect insulated mid-layer for keeping the cold at bay'.
It combines a water-resistant 700 fill power down - so pretty warm, but fends off the rain - with a Helium 30 outer shell, which is a very densely woven fabric to reduce heat loss.
So not only is it light, weather proof and warm, the whole thing packs away into one of its hand pockets with the aid of a karabiner carry loop, while there are also elastane bound cuffs and adjustable dual tether hem drawcords to fit accordingly.
So, for the relatively minimal price tag and weight, this could well be the ideal jacket as a mid-layer - underneath the Arete jacket, for instance - or can be used as a regular stand-alone jacket thanks to its simplistic style.
PHDesigns Yukon Down Pullover: K Series
In the Yukon Down Pullover, PHDesigns has produced something fitting for serious mountaineers looking to tackle arctic conditions.
Built for any temperatures down to minus 15 degrees, the Yukon jacket is made with 1000 fillpowerd down - that's a whole lot of warmth for the weight, which you can combine with one of PHD's new sleeping bags for a seriously toasty experience.
So there's even less chance of warm seeping out, it's also a pull over without a main front zip, which makes it an overall lighter garment and means it's easier to throw on when super cold.
The price is eye-wateringly high, but if you're an expeditionist then there won't be many better warm garments out there.
Berghaus Extrem Micro Down Jacket
Designed to be an on-the-go warm layer, the Berghaus Extrem Micro Down is a super-versatile number that can be used for climbing and skiing as well as mountain walking and trekking.
What makes it really cool (in terms of x-factor rather than heat) is the body-mapping technology, which ensures there's a correct balance of warmth distributed exactly where it's needed. This means it can act as a great warm layer under a shell like the Berghaus Thunder to battle the elements.
So we know it's warm in the right places, but will it still keep you happy if it gets damp. 'Yes' is the answer. For at least 16 hours, the latest hydrophobic down technology from Nikwax means the filling keeps most of its insulation value even when the going gets wet, by ensuring that the down clusters keep lofting rather than wilting.
It may be slightly heavier than the others on the this list, but 414g still ain't exactly going to weigh you down, and with a lifetime guarantee on each purchase, it may be worth a look.
Haglöfs L.I.M Essens Jacket
The jacket that stands for 'Less Is More' certainly achieves what it's set out to do with an ultra-lightweight construction.
Weighing in at just 180 grams, the Haglöfs L.I.M Essens has been designed to stow small, carry light but still have that serious down jacket warmth.
If you're an alpinist, adventure racer or simply just packing light for an adventure, this could be your go-to jacket especially considering it's actually deceptively durable thanks to a 7 Denier Nylon face fabric.
The sleeves are also articulated to give any mountaineers more movement during outdoors activities, while the price tag is premium, but you get one of the best warmth to eight ratios around.
Mountain Hardwear Ghost Whisperer Hooded Down Jacket
Dubbed the world's lightest full-featured hooded down jacket, the Mountain Hardwear Ghost Whisperer Hooded Down was developed with famous Swiss mountaineer Ueli Steck.
It's been designed to be as light as they come and MH has done a pretty good job of it. It's so light that's it's possibly lost some if its warmth qualities, but works brilliantly well as a mid-layer alternative.
It's essentially a lightweight, insulated windproof thanks to the combination of the Whisperer Ripstop outer fabric and the Q Shield Down 800-fill, which gives it warmth as well as water resistance.
So it's really been designed as an on-the-go warm layer, but at the same time it could be used as a stand-alone jacket with windproofing capabilities. Expensive, but if you're after super lightweight gear, here's what you're looking for.