# Temperature Conversion Rule of Thumb

This is not the best way to convert between Fahrenheit and Celsius! But it is the quickest, especially if you are doing the math in your head.

F = 2C + 30

This means that the temperature in Fahrenheit is equal to 2 times the degree in Celsius + 30. So if it is 10 degrees Celsius then 10 doubled is 20 and then 20 plus 30 is 50 Fahrenheit.

You can also convert the other way with the equation below.

C = (F – 30)/2

Warning! This is not exact at all.

The real equations are F = (9/5)C + 32 and C = (5/9)(F-32)

So if the AWOS gives you the temperature in Celsius and you just want to decide if you will need a sweater, then go ahead and use this rule of thumb.

If you need the information for calculating performance, then this rule of thumb is inappropriate to use and there is a much better way.

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