Looking at the next-to-last map titled, “Precipitation patterns averaged across all La Niña winters since 1950,” I see a demarcation at the northern border of California and the southern border of Oregon that doesn’t look natural because it strictly follows the border. There are also similar changes across state boundaries for Tennessee & North Carolina; Kentucky & Virginia; and West Virginia & Virginia. Are these changes in average precipitation at state boundaries due to extrapolating data because of a paucity of stations gathering data in those areas? Similar demarcations for average temperature do not appear at those boundaries in the preceding map titled, “Temperature patterns averaged across all La Niña winters since 1950.”