While connections between climate and the human mind and culture are widely acknowledged, they are not thoroughly quantified. Analyzing 100,000 paintings and data on 2,000 artists from the 13th to 21st centuries, the study reveals that the lightness of the paintings exhibited an interesting U-shaped pattern mirroring global temperature trends. There is a significant association between the two, even after controlling for various factors. Event study analysis using the artist-level data further reveals that high-temperature shocks resulted in brighter paintings in later periods for artists who experienced them compared to the control group. The effect is particularly pronounced in art genres that rely on artists' imaginations, indicating a notable influence on artists' minds. These findings underscore the enduring impact of climate on the human mind and culture throughout history and highlight art as a valuable tool for understanding people's minds and cultures.