The conversion

1200°F = 648.89°C

°C = (°F − 32) × 5/9, so (1200 − 32) × 5/9 = 648.89.

1200 °F is well outside the range outdoor air occupies on Earth, so there is no useful weather description for it — this page is arithmetic rather than a forecast.

Convert something else

68°F

The range either side

Neighbouring values, for when the number you actually wanted was a degree or two away.

Fahrenheit to Celsius either side of 1200 °F.
FahrenheitCelsius
1195 °F646.11 °C
1196 °F646.67 °C
1197 °F647.22 °C
1198 °F647.78 °C
1199 °F648.33 °C
1200 °F648.89 °C
1201 °F649.44 °C
1202 °F650 °C
1203 °F650.56 °C
1204 °F651.11 °C
1205 °F651.67 °C

The other direction

648.89 °C converts back to 1200 °F, which is the same relationship read the other way. Going from Celsius to Fahrenheit, multiply by 9/5 first and then add 32. Adding first is the usual mistake.

The full converter handles any value, in either direction, including kelvin, and shows the formula as it works.