This is a preview of a member exclusive premium article.


The Paramo Ostro Ultra Light Jacket is a new ultralight version of the popular Ostro Windproof Jacket. It has a full-length zipper and offers a range of features not often found on so light a windproof jacket. As a regular user of Paramo clothing, I was intrigued: how water resistant would this new ultra-light fabric be in comparison to the heavier weight fabrics in the Paramo range?

This jacket will probably be of interest to the following hikers:

  • Walkers who like to take a windproof jacket as well as a lightweight rain jacket for when conditions get really bad.
  • Trekkers who prefer to use a poncho for bad weather and shelter, leaving them free to wear just a light windproof the rest of the time.
  • Trekkers and walkers who prefer to use an umbrella and windproof instead of a fully waterproof jacket.
  • Trekkers and walkers hiking in warm regions where rain is brief and usually the result of thunderstorms in the afternoon.
Paramo Ostro Ultra Light Windproof Jacket 1
Photo: Paramo Directional Clothing

Features & Specifications

The new Ostro Ultra Light Jacket is lighter than any other comparable item in the Paramo line.  It can be combined with a Paramo fleece to produce a waterproof system equivalent to a Nikwax Analogy waterproof. Among the features found on the Ostro Ultralight Jacket are:

  • Internal stuff pocket with loop for attachment for easy carrying
  • Securable, adjustable helmet-friendly hood with dual adjustment and a low profile peak
  • Temperature control from ventilation zips that also provide access to internal pockets
  • Waist drawcord
  • Full-length front zip
  • Weight: 4.09 oz (116 g)

Review Context

I increasingly find myself not wearing my waterproof jacket during the summer trekking season. So I was intrigued by the versatility and weight of this windproof. My thought was that it could combine with other pieces of gear to create an ultralight waterproof system.

Paramo is well known for its highly breathable windproof jackets. They are not totally waterproof like membrane-based systems, but most people are genuinely surprised by just how water-resistant they are. On the other side of the equation is breathability, which is much higher than conventional membrane-based garments. So what one loses in one respect, one gains in the other.

When wearing a windproof, I’m looking at the following qualities:

  • Water resistance
  • Breathability
  • Drying speed
  • Simplicity (not too many bells and whistles)
  • Good fit
Paramo Ostro Ultra Light Windproof Jacket 2
The unboxed weight was 1 g less than advertised (Photo: Matthew Pullan).

Given the simplicity of these garments, it may surprise some people to know that I find some features unnecessary. For instance, I never use hood volumizers or waist drawcords, so I immediately removed them from this jacket. That got the weight down to a very respectable 3.63 oz (103 g).

Paramo Ostro Ultra Light Windproof Jacket 3
After trimming the hood volumizer and waist drawcord, the Ostro was 13g lighter than advertised (Photo: Matthew Pullan).

Description of Field Testing

These kinds of ultralight jackets are primarily intended for high energy activities where the body heat generated outweighs the need for complete water resistance.

I am active mainly in the Austrian Alps both summer and winter. I engage in a variety of activities, including paragliding, trekking, and amateur radio. As these involve carrying lots of additional items, like radios and gliders, these activities all benefit from having the lightest core gear available. My activities also involve a lot of sitting down in windy conditions, which leads to rapid heat loss.

For this review, I tested the Ostro Ultra Light in the conditions for which it was probably intended: warm alpine weather with sudden occasional thunderstorms in the afternoon. I took the Ostro Ultra Light on the Reichenstein Traverse in the Obersteiermark, a multi-day trek involving scrambling in places. While the weather was generally baking hot, the odd cold front did pass through, providing the perfect type of rain showers to fully test this jacket.

20180816 123121
The Reichenstein Traverse (Photo: Matthew Pullan).

Camping at elevation also meant some pretty chilly starts in the morning; these were the times when I most often wore the jacket (over my Golite Cirrus Down Vest), rather than for protection from bad weather. I also took the jacket on excursions in more temperate weather conditions, from sunny south-facing mountains to 6,561 ft (2000 m) mountains in very unstable conditions. Overall, I have spent the entire summer using this jacket at every opportunity.

Paramo Ostro Ultra Light Windproof Jacket 4
A spring thunderstorm puts the Ostro Ultra Light Windproof Jacket to the test (Photo: Matthew Pullan).

Performance Assessment

When reviewing the Paramo Ostro Ultra Light Windproof Jacket, I used the following aspects and characteristics for the performance assesment:

  • Finish Quality
  • Fit and Comfort
  • Hood
  • Wrist Cuffs
  • Hem
  • Zipper
  • Breathability and Ventilation
  • Weight and Compressibility

--- End of free preview ---
Member Exclusive

A Premium or Unlimited Membership* is required to view the rest of this article.


* A Basic Membership is required to view Member Q&A events