Multi-century evaluation of Sierra Nevada snowpack

The exceptional character of the California 2012–2015 drought has been revealed in millennium-length palaeoclimate records, but no long-term historical context is available for the recent snowpack decline. Here, we present an annually resolved reconstruction of 1 April SWE conditions over the whole Sierra Nevada range for the past 500 years. Our reconstruction of snow water equivalent reveals that the 2015 low is unprecedented in the context of the past 500 years.