The start of the winter season is marked by holiday carolers, hot cocoa, and in some parts of the world, blustery weather. Whether you enjoy bundling up in your coziest gear or are already counting down the days until spring, here are 15 facts about what’s happening outdoors this time of year.

1. IT SOMETIMES SNOWS WHERE YOU LEAST EXPECT IT.

You wouldn’t be shocked to see snow on the ground of Siberia or Minnesota when traveling to those places during the winter months. But northern areas don’t have a monopoly on snowfall—the white stuff has been known to touch down everywhere from the Sahara Desert to Hawaii. Even the driest place on Earth isn’t immune. In 2011, the Atacama Desert in Chile received nearly 32 inches of snow thanks to a rare cold front from Antarctica.

2. SNOWFLAKES COME IN ALL SIZES.

The average snowflake ranges from a size slightly smaller than a penny to the width of a human hair. But according to some unverified sources they can grow much larger. Witnesses of a snowstorm in Fort Keogh, Montana in 1887 claimed to see milk-pan sized crystals fall from the sky. If true that would make them the largest snowflakes ever spotted, at around 15 inches wide.

3. A LITTLE WATER CAN ADD UP TO A LOT OF SNOW.

The air doesn’t need to be super moist to produce impressive amounts of snow. Unlike plain rainfall, a bank of fluffy snow contains lots of air that adds to its bulk. That’s why what would have been an inch of rain in the summer equals about 10 inches of snow in the colder months.

4. YOU CAN HEAR THUNDERSNOW WHEN THE CONDITIONS ARE RIGHT.

If you’ve ever heard the unmistakable rumble of thunder in the middle of a snowstorm, that’s not your ears playing tricks on you. It’s likely thundersnow, a rare winter weather phenomenon that’s most common near lakes. When relatively warm columns of air rise from the ground and form turbulent storm clouds in the sky in the winter, there’s potential for thundersnow. A few more factors are still necessary for it to occur, namely air that’s warmer than the cloud cover above it and wind that pushes the warm air upwards. Even then it’s entirely possible to miss thundersnow when it happens right over your head: Lightning is harder to see in the winter and the snow sometimes dampens the thunderous sound.

5. SNOW FALLS AT 1 TO 6 FEET PER SECOND.

At least in the case of snowflakes with broad structures, which act as parachutes. Snow that falls in the form of pellet-like graupel travels to Earth at a much faster rate.

6. IT DOESN’T TAKE LONG FOR THE TEMPERATURE TO DROP.

Don’t take mild conditions in the middle of January as an excuse to leave home without a jacket. Rapid City, South Dakota’s weather records from January 10, 1911, show just how fast temperatures can plummet. The day started out at a pleasant 55°F, then over the course of 15 minutes a wicked cold front brought the temperature down to 8 degrees. That day still holds the record for quickest cold snap in history.

7. THE EARTH IS CLOSEST TO THE SUN DURING THE WINTER.

Every January (the start of the winter season in the northern hemisphere) the Earth reaches the point in its orbit that’s nearest to the Sun. Despite some common misconceptions, the seasonal drop in temperature has nothing to do with the distance of our planet to the Sun. It instead has everything to do with which direction the Earth’s axis is tilting, which is why the two hemispheres experience winter at different times of the year.

8. MORE THAN 22 MILLION TONS OF SALT ARE USED ON U.S. ROADS EACH WINTER.

That comes out to about 137 pounds of salt per person.

9. THE SNOWIEST CITY ON EARTH IS IN JAPAN.

Aomori City in northern Japan receives more snowfall than any major city on the planet. Each year citizens are pummeled with 312 inches, or about 26 feet, of snow on average.

10. SOMETIMES SNOWBALLS FORM THEMSELVES.

Something strange happened earlier this year in northwest Siberia: Mysterious, giant snowballs began washing up on a beach along the Gulf of Ob. It turns out the ice orbs were formed naturally by the rolling motions of wind and water. With some spheres reaching nearly 3 feet in width, you wouldn’t want to use this frozen ammunition in a snowball fight.

11. WIND CHILL IS CALCULATED USING A PRECISE FORMULA.

When the weatherman reports a “real feel” temperature of -10 degrees outside, it may sound like he’s coming up with that number on the spot. But wind chill is actually calculated using a complicated equation devised by meteorologists. For math nerds who’d like to test it at home, the formula reads: Wind Chill = 35.74 + 0.6215T – 35.75(V^0.16) + 0.4275T(V^0.16).

12. CITIES ARE FORCED TO DISPOSE OF SNOW IN CREATIVE WAYS.

When snow piles up too high for cities to manage, it’s usually hauled away to parking lots or other wide-open spaces where it can sit until the weather warms up. During particularly snowy seasons, cities are sometimes forced to dump snow in the ocean, only to be met with criticism from environmental activists. Some cities employ snow melters that use hot water to melt 30 to 50 tons of snow an hour. This method is quick but costly—a single machine can cost $200,000 and burn 60 gallons of fuel in an hour of use.

13. WET SNOW IS BEST FOR SNOWMAN-BUILDING, ACCORDING TO SCIENCE.

Physics confirms what you’ve likely known since childhood: Snow on the wet or moist side is best for building your own backyard Frosty. One scientist pegs the perfect snow-to-water ratio at 5:1.

14. SNOWFLAKES AREN’T ALWAYS UNIQUE.

Snow crystals usually form unique patterns, but there’s at least one instance of identical snowflakes in the record books. In 1988, two snowflakes collected from a Wisconsin storm were confirmed to be twins at an atmospheric research center in Colorado.

15. THERE’S A DIFFERENCE BETWEEN FREEZING RAIN AND SLEET

Freezing rain and sleet can both have scary effects on driving conditions, but their formations differ in some key ways. Both types of precipitation occur when rain formed in warm air in the sky passes through a layer of cold air near the ground. Thicker layers of cold air create sleet, a slushy form of water that’s semi-frozen by the time it reaches the Earth. Thinner layers don’t give rain enough time to freeze until it hits the surface of the ground—it then forms a thin coat of ice wherever it lands.

Winter weather can be unpredictable, which is why GEICO’s Emergency Roadside Service is available 24/7 via the GEICO mobile app. If you need a tow, a jump start, help fixing a flat tire, or if you lock your keys in the car, help can be dispatched with just a few taps of the finger.