A rain jacket should be breathable
Lightweight rainwear that is breathable and can be used for everyday wear and longer trips. Unsure about the size? Call or write!
Breathable rain jackets keep you dry from the inside and not just from the outside, as we normally expect a rain jacket to do.
80% of all the energy used by the body during physical activity turns into heat energy. In order to prevent the body from overheating, we sweat. Sweat mainly consists of water, and the heat energy coming from the body causes the water to evaporate. Evaporation requires heat and thereby removes heat energy from the body. However, this only works if the vapor can escape. If you wrap yourself in a plastic bag, you will quickly feel very hot. That is why fabric has been developed which can allow some of the moisture to escape in the form of vapor. The more moisture that can pass through the fabric, the better the breathability.
Breathable rainwear can thus keep water out while allowing moisture to escape from the inside. It's super smart.
Breathability is measured in grams of water that can penetrate the fabric per square meter per hour or per 24 hours (g/m2*h or g/m2*24). The desired breathability of the rain jacket depends on your activity level and not everyone sweats the same amount. As a starting point, it can be said that sedentary/light activity (light walk) requires a breathability of about 300 - 3,000 g/m2*24. Moderate/high activity (running) requires a breathability of about 8,000 to 16,000 g/m2*24. Extreme activity (marathon and ironman) requires a breathability of about 20,000 g/m2*24.
If you are going hiking with a backpack, you should aim for a breathable rain jacket that falls within the range between light and moderate activity. A rain jacket with a breathability of about 3,000 to 5,000 g/m2*24 will be sufficient for most hikes, depending on the level of difficulty.
A good, breathable rain jacket can make the difference between being pleasantly warm or freezing cold. When you are wet, there is a greater risk of freezing, and at the same time, your body needs to be able to get rid of its heat so that you do not overheat. It is therefore not completely insignificant whether you wrap yourself in a garbage bag or a rain jacket from, for example, Didriksons.