USDA NAIP 2018 aerial imagery (60cm resolution) for California is now publicly available through GIS-compatible services hosted by the California Department of Fish and Wildlife (CDFW). Four different 2018 services are offered (4-band, natural color, CIR, and NDVI) and add to the NAIP services CDFW also provides for earlier years. Some of the imagery along the California/Mexico border was actually flown in 2019. Please see this page for further information and to download ArcGIS layer files (.lyr) for easy access: https://wildlife.ca.gov/Data/GIS/Map-Services
The NAIP 2018 natural color and CIR imagery services are also viewable as basemaps in CDFW’s BIOS map viewer. Click the BIOS Viewer button – then the Basemaps button in the upper left corner then scroll down the list and pick NAIP 2018 or NAIP 2018 CIR: https://wildlife.ca.gov/Data/BIOS
Note that USDA is also currently serving California’s NAIP 2018 imagery (natural color only) as part of their nationwide CONUS PRIME service available via: http://hub.arcgis.com/datasets/e74cf6b0790e424489bbe84cbc0dc7ad
NAIP 2018 county mosaics for California are available to download from the USDA Geospatial Data Gateway: https://datagateway.nrcs.usda.gov/GDGHome_DirectDownLoad.aspx
This information is provided by Will Patterson of the Biogeographic Data Branch, Department of Fish and Wildlife. Will may be contacted at William.Patterson@wildlife.ca.gov or by phone at (916) 323-1484.