These are the long-term average conditions, i.e. the climate normals, at the station. The bracketed comparisons on the monthly, annual and daily reports are measured against them.
Source: PRISM 1991-2020 800 m normals, cell center 37.4667,-122.2667 (station approx 37.470,-122.265, Emerald Lake Hills)
Period: 1991-2020
Temperature and rainfall normals are PRISM Climate Group (Oregon State University) 1991-2020 800 m gridded monthly normals, sampled at the grid cell centred on 37.4667, -122.2667 that contains the station (approx. 37.470, -122.265, Emerald Lake Hills, ~125 m above sea level).
Adjustments were made for the sensor's location (hillside thermal belt).