This jacket is so light, you might think you forgot to pack it.

We’ve had our share of puffy jackets in our day. Down or synthetic, light or heavy, you name it. But we’ve never had one like Patagonia’s Micro Puff. It’s a jacket for every month of the year.

It’s no secret: Patagonia isn’t cheap. It’s also no secret that the company is a fierce advocate of public lands, environmentalism, recycling, humanitarianism, fair trade and corporate responsibility (see Black Friday 2016, when the company donated 100 percent of its sales to grass-roots environmental efforts, to the tune of $10 million). So, knowing your dollars are being used to support a good cause, or several, helps ease the sting a bit. The rest of the sting is stifled when the product works better than expected.

At 11 ounces, the Patagonia Micro Puff is possibly the warmest jacket for its weight. It’s puffy and cozy, and noticeably tough. The secret is under the burly Pertex durable water-resistant shell: A synthetic PlumaFill mimics the shape and thermal properties of natural down. Instead of using long baffles stuffed with insulation, it’s quilted, like your grandmother’s blanket.

Puffy, cozy, and noticeably tough.Bee Alaine Mathis

You can stuff it in its own pocket, and being a synthetic, it works just as well when soaked if you get wet – like that time you were stuck belaying your partner forever while she was stuck climbing ice and then it started raining … in January.

But this is not just a winter piece. Trail race packet pick-ups on frigid spring mornings in the desert, 30-degree camper trailers with no heat, summer dawn rendezvous at 11,000 feet – it’s all good. Stuff it in your climbing kit this fall when 60-degree days turn to 40-degree nights. It is flawless under an outer layer for 9-degree first chairs at Wolf Creek with 20 mile-per-hour winds. Oh, and it’s just right for chilly nights downtown.

$249 ($299 for the style with a hood)