Fig. 4
Boxplots of monthly RMSE, MAE, and Bias for sWBGT in 2022, comparing ERA5-derived values to ISD observations for the Northern Hemisphere (left) and Southern Hemisphere (right). The boxes extend from the first quartile (Q1) to the third quartile (Q3) of the data, representing the interquartile range (IQR). The black line within each box indicates the median, reflecting the central tendency of the error metrics. Whiskers extend from the boxes by a factor of 1.5 times the IQR, capturing the range of non-outlying data points. Gray circular points represent outliers, defined as values beyond Q3 + 1.5 × IQR or below Q1 - 1.5 × IQR. The mean for each metric and month is marked by a white triangle with a black outline. Colors distinguish the error metrics: red for RMSE, gray for MAE, and green for Bias, facilitating the identification of each metric’s distribution across months and hemispheres.
