Lakes are often defined by seasonal cycles. The seasonal timing, or
phenology, of many lake processes, such as primary productivity, are
changing in response to human activities. However, long-term records
exist for few lakes, and extrapolating patterns observed in these lakes
to entire landscapes is exceedingly difficult using the limited number
of in situ observations that are available. Limited landscape level
observations means we do not know how common shifts in lake phenology
are at macroscales. Here, we use a new remote sensing dataset,
LimnoSat-US, to analyze U.S. summer lake color phenology between 1984
and 2020 across more than 26,000 lakes. Our results show that summer
lake color seasonality can be generalized into five distinct phenology
groups that follow well-known patterns of phytoplankton succession. The
frequency with which lakes transition from one phenology group to
another is tied to lake and landscape level characteristics. Lakes with
high discharge and low variation in their seasonal extent are generally
more stable while lakes in areas with high interannual variations in
climate and catchment population density show less stability. Our
research reveals previously unexamined spatiotemporal patterns in lake
seasonality and demonstrates the utility of LimnoSat-US, which, with
over 22 million remote sensing observations of lakes, creates novel
opportunities to systematically examine changing lotic ecosystems at a
national scale.