Absolutely. In fact, people in Wisconsin are used to reading Fahrenheit in negative more than in positive. -1 F is just -18.3 C, which is cold but not very cold for those who live in the far north. read more
There's a rough and ready way round this, based on 9/5 being close to doubling and 5/9 being near half. Under this system, double your Centigrade and add 32 to find Fahrenheit. Alternatively, take Fahrenheit, subtract 32 and halve the answer to get to Celsius. read more