I will resolve this according to NASA's GISTEMP data here (or wherever it's available). The current 3rd warmest year, 2019, was 0.98° above the 1951-1980 base period. I'll count joint 3rd place as a NO, so currently the number has to be 0.99° or higher for a YES resolution. (That number may change if 2022 turns out to be in the top 3, if they change base periods, if they change past data for some reason, etc.) If GISTEMP isn't available, I'll look at NOAA, HadCRUT, or Berkeley Earth temperature data, in that order.

Edit 2023-02-02: It looks like they adjusted the number for 2019 to 0.97°, so now it has to be 0.98° or higher.

Edit 2023-04-20: Looks like they changed it back again. 0.99° or higher resolves YES, 0.98° or lower resolves NO.