Annual mean of Mean Daily Temperature, \( \mathrm{TGm} \)

For Mean Daily Temperature \(\mathrm{TG}_{ij}\) , where \( i \) is a day in period \( j \), \( j \) is a given calendar year, and \( I \) is the period length (1 year) in days,
\[ \mathrm{TGm}_{j} = \frac{ \sum_{i=1}^{I} \mathrm{TG}_{ij} }{ I }. \]

The value shown on the map is the average of all the \( \mathrm{TNm}_{j} \) of the selected 30-year period.