Friday, October 7, 2011

How to Write Temperature Degrees

It is finally cooling down in this dry state of Arizona. I've had my windows open for the past three days and have been loving every minute of it! Sixty-three degree Celsius* weather is where it's AT.

In honor of the changing temperatures, today's post will give you a quick guide on how to handle writing temperatures in different kinds of writing.

Writing Temperatures in Informal Writing

If you're not following a style guide and there's no need to stick to anything besides the basest of grammar rules...why are you even reading this? ;)

No, but really, in informal writing, you're welcome to write out numbers or use numerals, use a degree symbol (°) or spell it out, and abbreviate, spell out, or leave out Celsius and Fahrenheit. If you do choose to include them, Celsius and Fahrenheit (and their abbreviations, C and F, respectively) should still be capitalized.

Keyboard Shortcuts for the Degree Symbol

Mac: Option + Shift + 8 = °
PC: Alt + 0176 = °

Writing Temperatures in Academic Writing**

When writing for scientific pieces, use a numeral, the degree sign, and the abbreviation, with no spaces between any of the items:

17°C, 17°F

When writing something nontechnical (which is everything that is not scientific or mathematical), spell them out:

seventeen degrees Celsius, seventeen degrees Fahrenheit

Temperatures in AP Style

To shake things up, AP style suggests always using numerals for temperature, but to also always spell out the word "degrees."

Until next week, enjoy the cooling weather! I'll leave you with a picture from my parents' trip (as promised), where we're enjoying the seventy-degree weather in the Grand Canyon. If you've never been, you should go.

*As a friend has so kindly pointed out, 63°C is actually pretty unpleasant. It should read 63°F.

**This I confirmed in my trusty Chicago Manual of Style, v. 15. Interestingly, it suggests also verifying this information in AMA if your material is "highly technical."


  1. 63 celsius is 145 degrees fahrenheit...sound unpleasant to me ;-)


  2. what about if you want to write something more specific, like 15.5 degrees celcius. If you are using British English, is is .5 or ,5 ?

    1. The rule still applies as outlined above. British English uses the period, as well.

  3. What about just using the words without numbers? Would you capitalize in a sentence like the following? "Please use Fahrenheit or Celsius as a reference point."

  4. @Anonymous, yes, you would still capitalize in that situation.

  5. The vast majority of scientific & industry bodies, including the National Institute of Science and Technology, SI, ISO, etc., dictate a space between the numeral and the degree sign.

    From NIST:
    (a) The symbol °C for the degree Celsius is preceded by a space when one expresses the values of Celsius temperatures.
    Example: t = 30.2 °C but not: t = 30.2°C or t = 30.2° C

    From API:
    Use a non-breaking space between the degrees sign and the number for temperature references (98 °C, 100 °F).