As winter sets in, the indoors beckon to us. Three months of freezing temperatures, snow, wind and ice? Better just ride it out in front of the fireplace with a good book and a mug of hot chocolate. If that sounds right to you, you should reconsider. There are lots of reasons to get outside in the coldest months of the year: Here are seven of the best.

1. Experience a Whole New World

Winter brings about major changes in the natural world as animals and plant life adapt to snow and cold. A tree-lined rushing stream in summer looks completely different in winter, and has its own sort of beauty.

National parks are especially beautiful in the winter. In many, you can take advantage of the snow cover to explore a new landscape on ski, snowshoe or snowmobile.

2. Exercising in Cold Weather Is Good for You

Vincent Desjardins / CC

First of all, it's never too cold to work out outside. It may be unpleasant at first, but if you wear proper layers and keep moving, the body heat you generate will easily keep you safe from hypothermia.

In fact, exercising in cold temperatures does a lot of good. Aerobic exercise keeps your heart pumping and boosts your level of virus-killing cells, just when you most need them to fight off seasonal colds and flus. Want a simpler, even more compelling reason? Colder external temperatures make our bodies expend more energy to keep warm, so you burn more fat.

3. Sunlight Combats Depression

Seasonal affective disorder, sometimes called the wintertime blues, is a form of depression most common in the winter. Symptoms include weight gain, lethargy and hypersomnia. The most common treatment is bright light therapy, which simulates the beneficial effects of natural sunlight.

Not to say that spending time outside will save you from depression, but it's clear that spending months at a time inside, surrounded by artificial light, just isn't healthy.

4. Winter Sports

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This is the most obvious: sports like downhill and Nordic skiing, snowboarding and ice skating all require snow or ice (I refuse to acknowledge indoor skiing as a sport). No matter how engrossing the novel or realistic the video game, being inside can't compare with the thrill of racing down a mountain or pulling off a triple-axle.

5. Have a National Park All to Yourself

Winter is underrated, and that's good news for the few who are smart enough to take advantage of drastically thinned crowds to explore the country's national parks. Places like Yellowstone are more pristine when no one is around and offer a beauty that's totally different from what you see in the summer.

6. Grow Winter-Only Crops

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If you've got a green thumb, there's no reason to stop gardening just because it got chilly out. There are lots of delicious vegetables that thrive in cold weather, including cabbage, celery, radishes, kale and spinach.

You need a bit more foresight to plant them in the fall, but keeping your garden going is a great way to get outside during the winter, and to have fresh produce when you would normally be eating canned vegetables.

7. Earn Your Hot Chocolate

There's nothing wrong with building a roaring fire and enjoying a warm and toasty winter evening. But if you've been on the sofa all day, have you really earned it? More to the point, that hot chocolate will taste better and be a lot more satisfying if you just got back from an afternoon of snowshoeing or harvesting your winter crops.