The conversion

1000°F = 537.78°C

°C = (°F − 32) × 5/9, so (1000 − 32) × 5/9 = 537.78.

1000 °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 1000 °F.
FahrenheitCelsius
995 °F535 °C
996 °F535.56 °C
997 °F536.11 °C
998 °F536.67 °C
999 °F537.22 °C
1000 °F537.78 °C
1001 °F538.33 °C
1002 °F538.89 °C
1003 °F539.44 °C
1004 °F540 °C
1005 °F540.56 °C

The other direction

537.78 °C converts back to 1000 °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.