Talk about extreme weather changes. The moon's surface temperature varies by nearly 500°F, from -240°F when it is dark to 220°F in the sun. And once those extreme temps set in, they stick around for a while — a spot on the moon spends about 13 days in frigid darkness, followed by 13 days in water-boiling sunlight. The lack of atmosphere, which on Earth helps trap heat so it doesn't all dissipate at night, accounts for the wild temperature swings. However, if you dig a meter below the moon's surface, the temperature evens out to a nearly constant -31°F.