55 degrees Fahrenheit is equal to 12.78 degrees Celsius. To convert Fahrenheit to Celsius, we can use the formula (F - 32) x 5/9 = C, where F is the temperature in Fahrenheit and C is the temperature in Celsius. Plugging in 55 for F, we get (55 - 32) x 5/9 = 12.78°C. Therefore, 55°F is equal to 12.78°C.