It’s a common belief that getting caught in the rain can give you a cold. But in reality, rain doesn’t directly make you sick.

While rain itself doesn't transmit viruses, staying wet and cold for an extended period can lower your body temperature and weaken your immune system. When your immune defenses are down, you become more vulnerable to catching viruses like the cold or flu.

Does Rain Make You Sick?

Being caught in a rainstorm or running in the rain won’t make you sick, since viruses are not spread by water. In fact, cold and flu viruses tend to thrive in cold, dry air—not in the humid environment rain creates.

However, when you get wet and cold, your body may lose heat, which can weaken your immune response. For instance, cold weather can narrow blood vessels in your nose, reducing the delivery of white blood cells that fight off infections.

What Actually Causes a Cold?

Colds are caused by viruses, not rain. These viruses spread through contact with infected people or contaminated surfaces. Close indoor contact, especially during colder or rainy seasons, is the main reason illnesses are more common at those times.

On rainy days, people often spend more time indoors, increasing the chances of virus transmission through close contact.

Can Rain Cause Hypothermia?

Yes, being outdoors in cold weather, especially when wet, can lead to hypothermia. This occurs when your body loses heat faster than it can produce it. Even temperatures above freezing can cause hypothermia if you’re wet from rain or sweat.

Hypothermia is a serious condition that can be life-threatening. Warning signs include:

  • Confusion

  • Drowsiness

  • Fatigue

  • Loss of coordination

  • Memory problems

  • Shivering

  • Slurred speech

Since hypothermia can affect brain function, people may not realize they’re in danger. Seek medical help immediately if someone shows these symptoms after being exposed to the rain.

Tips for Staying Healthy in Rainy Weather

Keeping your body warm and dry is the best way to avoid illness and prevent hypothermia when it's raining. Here are a few tips:

Check the Weather Forecast

Stay informed about upcoming weather conditions to prepare appropriately. Dress in layers, and always carry extra clothing if you’re going to be outdoors.

Wear Waterproof, Breathable Gear

Use a waterproof jacket with breathable fabric to stay dry without overheating. Look for jackets with a durable water-repellent (DWR) coating. If your gear isn’t repelling water anymore, it may need to be re-treated.

Avoid Cotton

Cotton absorbs and holds moisture, which makes you feel cold. Wet cotton clothing, especially undergarments and socks, can draw heat away from your body.

Use Moisture-Wicking Base Layers

Choose base layers made of wool, nylon, or polyester. These materials wick sweat and moisture away from your skin, helping you stay warm and dry.

Cover Your Head

Wear a waterproof hat or use a hood to protect your head and face from rain. This will help retain heat and improve visibility in heavy rain. Wet hair won’t make you sick, but it can contribute to feeling cold.

Change Into Dry Clothes Promptly

Once you get inside, remove wet clothing as soon as possible. Staying in damp clothes will continue lowering your body temperature. Keep spare dry clothes and a towel in your car or bag if you're going out.

Drink Something Warm

A warm beverage can help raise your internal body temperature. Carry a thermos of tea or coffee, or warm up with hot cocoa or soup once you're indoors.

A Quick Review

Rain itself doesn’t cause illness, but being cold and wet can reduce your immune system’s effectiveness and increase your risk of getting sick. To stay healthy in rainy conditions, wear moisture-wicking clothes, waterproof outerwear, and change into dry clothes quickly after getting wet.