NPP and N20 VIIRS Reanalysis v2 (RAN2) Global SST data are produced at NOAA STAR, 
using the Advanced Clear-Sky Processor for Ocean (ACSPO) SST system version 2.61.
For dates after 30 Apr 2019 this RAN2 product is complemented by the VIIRS near real-time (NRT) data 
found at ftp://ftp.star.nesdis.noaa.gov/pub/socd2/coastwatch/sst/nrt/viirs/

NPP RAN2 covers the period from 1 Feb 2012 to present
N20 RAN2 covers the period from 5 Jan 2018 to present
Data are organized by Platform/Level/YYYY/DDD.

Data are provided in GHRSST Data Specification v2 (GDS2) NetCDF format, 
as L2P (swath) and L3U (gridded, 0.02deg). Note that the archive on this
ftp server only contains L3U data (0.4GB/day) due to data storage limitations.
A complete archive of corresponding L2P data (26GB/day) can be obtained from PODAAC with the following DOI:

NPP L2P: http://dx.doi.org/10.5067/GHVRS-2PO61
N20 L2P: http://dx.doi.org/10.5067/GHV20-2PO61
NPP L3U: http://dx.doi.org/10.5067/GHVRS-3UO61
N20 L3U: http://dx.doi.org/10.5067/GHV20-3UO61

Further information on the data can be found at the following links.

CoastWatch:
https://coastwatch.noaa.gov/cw/satellite-data-products/sea-surface-temperature/acspo-viirs.html

NCEI:
NPP L2P: https://doi.org/10.7289/v5pr7sx5
N20 L2P: https://doi.org/10.25921/sfs7-9688
NPP L3U: https://doi.org/10.7289/v5kk98s8
N20 L3U: https://doi.org/10.25921/7c1m-rw73