Is Merino Wool Warm? Comparison With Other Fabrics

Merino wool is great for all temperatures. But it’s winter where this fabric really shines. Merino wool provides warmth to the wearer, and does so without being chunky or too thick.

But just how warm is merino wool? Everyone knows that it will keep you warm, but the degree of warmth is something that most people don’t talk about. And that’s exactly what I am going to do in this article.

Here’s the warmth of merino wool compared to other fabrics in a nice little table.

FabricWarmthWarmth When Wet
Merino Wool4/55/5
Regular Wool3/54/5
How warm are different fabrics compared to each other.

Since warmth can be measured only in comparison, I took 6 different sweaters I owned, made up of different fabrics, and pitted them against one another. I gave them a rating out of 5 and made separate categories for warmth and warmth provided when wet.

Due to this analysis, I came to a definite conclusion.

Merino wool is a very warm fabric. It is much warmer than cotton, polyester, and regular wool. Only lambswool and cashmere manage to give it competition in terms of warmth. Cashmere is slightly warmer than merino wool, while lambswool is almost at the same level in terms of heat retention.

If you are going hiking, then merino is going to be a much better choice than lambswool, as lambswool isn’t that warm when it gets wet. It also shrinks much less in comparison, which is again a positive.

Why Is Merino Wool Warm?

warm merino wool sweater

There is a special reason behind the warmth of merino wool. Merino wool fibers tend to have a natural crimp in their structure which works wonderfully to trap our body heat. By having this unique weave, they don’t let the heat from our body dissipate, and thus merino is a very warm fabric.

And just think about it for a moment; merino wool comes from the merino sheep that can endure temperatures as low as 5 degrees. If the wool can keep them warm, then it surely can keep us warm.

By trapping the body heat and not letting it go out, merino wool fibers also perform another important function; they don’t let the cold air in. It is due to this reason that merino wool sweaters make a great top layer during the fall season and a great base layer during the winter one.

Is Merino Wool Warmer Than Regular Wool?

Merino wool is much warmer than regular wool. While normal wool depends upon its thickness in order to generate heat, merino wool is warm on its own due to the unique structure of its fibers.

Although both merino wool and regular wool remain warm when wet, the difference in warmth is immense. Merino wool sweaters stay much, much warmer when exposed to water.

Another reason for preferring the merino variant over regular wool is that regular wool cannot be used as a base layer. Because it is so thick, layering some garments over it becomes next to impossible. However, merino wool circumvents this problem due to the thinness of its fibers.

Is Merino Wool Warmer Than Cotton?

Merino wool is a lot warmer than cotton. Cotton is essentially a summer fabric, and it cannot be used in harsh winters. Merino on the other hand works well round the year because of its intelligent heat-management properties.

Cotton becomes useless in terms of heat when it becomes wet. It gets drenched pretty quickly and starts clinging to the body. This makes the wearer feel even colder, and can potentially be a major problem if you are into hiking or camping.

The only advantage cotton has over merino wool is that it is thinner than merino, which allows you to layer more efficiently. However, there are many premium quality merino sweaters that are extremely fine and can be used in place of cotton.

Is Merino Wool Warmer Than Cashmere?

No, merino wool is not warmer than cashmere. The fibers of cashmere are much better at heat retention, and thus cashmere would be a better option for extreme winters.

Cashmere, like merino wool, also tends to stay warm when wet. It does not cling to the body, and continues to provide heat. But in my opinion, merino wool sweaters tend to do a better job at warming the human body if they are wet.

Also, if you are going hiking or camping, I would recommend you to take some merino wool clothing instead of cashmere. Cashmere, although durable, is more of a luxury fabric. Merino wool on the other hand is a utilitarian fabric, and will keep you warm no matter what the external conditions are.

Frequently Asked Questions

Is merino wool warmer than polyester?

Merino wool is quite warmer than polyester on its own. However, cashmere-polyester blends tend to be equivalent to merino wool in terms of warmth. Cotton-polyester blends are inferior to merino wool.

Is merino wool warmer than lambswool?

Lambswool (or Virgin wool) is warmer than merino wool when dry. But a wet merino wool garment is warmer than a wet lambswool garment.

Is merino wool warmer than fleece?

Merino wool is a lot warmer than fleece. Fleece is useless for warmth if it gets wet, as it gets saturated with rainwater very quickly.

Final Remarks

Merino wool is a very warm fabric, as its fibers have a natural crimp that works to trap body heat. Sheared off of merino sheep that can endure temperatures as low as 5 degrees, merino wool can be surprisingly thin, which means you can wear layers, which again add to the overall warmth of your outfit.

And that last point is important, because it’s not something that you can do with thicker fabrics like fleece.

Finally, if blended with other warmer fabrics like cashmere, merino wool can prove to be even warmer.