Correction to: Nature Climate Change https://doi.org/10.1038/s41558-021-01112-8. Published online 5 August 2021.

In the version of this article initially published, there was a presentation error in Figure 2d–f where brackets, indicating nonsignificant differences between study periods, appeared for all months in the figure. The brackets have been now removed from significant differences in the HTML and PDF versions of the article.