Data is currently at
https://data.giss.nasa.gov/gistemp/tabledata_v4/GLB.Ts+dSST.csv
or
https://data.giss.nasa.gov/gistemp/tabledata_v4/GLB.Ts+dSST.txt
(or such updated location for this Gistemp v4 LOTI data)
The relevant figure for resolving this question is the J-D column for the 2024 year.
January 2024 might show as 122 in hundredths of a degree C, this is +1.22C above the 1951-1980 base period. If it shows as 1.22 then it is in degrees i.e. 1.22C. Same logic/interpretation as this will be applied.
If the version or base period changes then I will consult with traders over what is best way for any such change to have least effect on betting positions or consider N/A if it is unclear what the sensible least effect resolution should be.
Numbers expected to be displayed to hundredth of a degree. The extra digit used here is to ensure understanding that +1.20C does not resolve an exceed 1.205C option as yes.
First plausible number I see or is pointed out to me shall be used for resolution. This is so that subsequent revisions to data should not cause re-resolution unless there is a clear problem with the first resolution data used.