In the lower part of the atmosphere, known as the troposphere, the temperature generally drops at a rate of about 2.5 degrees per 1,000 feet on a cloudy, humid day to about 4 degrees per 1,000 feet on a sunny, dry day. But the rate can vary depending on atmospheric conditions.
The temperature gradually drops until you get to about 38,000 feet, where it's about 75 degrees below zero Fahrenheit. At that point, you reach the stratosphere, where the temperature goes up again until you're about 30 miles up, peaking up around 20-25 degrees above zero.
Beyond that, it takes a series of dips and spikes, until it reaches the outer edge 55 miles up, where it's over 1,000 degrees, but the air is so thin, it'd feel cold to human touch.
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