They are incorrect. Blue is lower than the average between 1961-1990 while red is higher.
Technical notes: this graphic uses the HadCRUT5 dataset with ‘average’ defined as 1961-1990. The map for 2023 is based on January to September only; all other years are annual averages with at least 6 months of data available for that location. White areas show where not enough data is unavailable.
They are incorrect. Blue is lower than the average between 1961-1990 while red is higher.