Accurist
A person who insists upon accuracy, especially in verbal and written communication. A person who does not permit use of one's best guess in lieu of actual fact. A person with a low tolerance for creative license outside of artistic endeavors.
"It's two degrees outside."
"It is precisely thirty-six degrees Fahrenheit."
"I'm just saying it's cold out, quit being such an accurist!"
"It is precisely thirty-six degrees Fahrenheit."
"I'm just saying it's cold out, quit being such an accurist!"