The conversion

300°F = 148.89°C

°C = (°F − 32) × 5/9, so (300 − 32) × 5/9 = 148.89.

300 °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 300 °F.
FahrenheitCelsius
295 °F146.11 °C
296 °F146.67 °C
297 °F147.22 °C
298 °F147.78 °C
299 °F148.33 °C
300 °F148.89 °C
301 °F149.44 °C
302 °F150 °C
303 °F150.56 °C
304 °F151.11 °C
305 °F151.67 °C

The other direction

148.89 °C converts back to 300 °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.