Time of emergence of summer warming beyond the baseline temperature variability. The color contours show the last year in which the departure of summer temperature from the 1970-1999 baseline is less than two standard deviations of the 1970-1999 temperature variability. The departure and baseline variability are calculated as the mean of the values in the five RegCM3 members. In the top panel, the annual departures are calculated from the 21st century annual summer temperature timeseries, and the baseline variability is calculated as the interannual standard deviation of the 1970-1999 annual summer temperature timeseries. In the bottom panel, the annual departures are calculated from the 10-year running mean of the 21st century annual summer temperature timeseries, and the baseline variability is calculated as the interannual standard deviation of the 10-year running mean of the 1970-1999 annual summer temperature timeseries. As described in the Methods, because we cannot confirm permanent emergence beyond the end of the 21st century, we disregard all final emergence dates that occur after 2080.