HARPS-N observations of the Sun (top) with each exposure marked by a point (Dumusque et al. 2021). Selected exposures at the smallest airmasses (red points) occurred around daily noon during the summer seasons of 2016–2017–2018. Airmasses for the 1000 selected recordings (middle). S/N values remaining very high, but decreasing slightly over time (bottom), apparently due to diminishing telescope and instrument transmission.