A comprehensive list of realtime measurements and data analyses and products related to El Niño / La Niña

In situ and Climate Data

• Tropical Pacific Conditions: Real-time TAO El Nino buoy data
  from the NOAA/PMEL Global Tropical Moored Buoy Array
• State of the ocean climate - ENSO indices | Atmosphere | Surface ocean | subsurface ocean | sea ice
  from NOAA Ocean Observations Panel for Climate
• Global drifting buoys
  from NOAA AOML
• Argo profiling floats
  from NOAA PMEL, the US Data Assembly Center (DAC), OceanOps, and the Argo global data centers USGODAE and IFREMER.
• Sea level data
  from the University of Hawaii Sea Level Center
• XBT/XCTD
  from Scripps Institution of Oceanography
• Realtime climate maps | US Climate plotting | Sea Surface Temperature animations
  from NOAA Physical Sciences Laboratory
• Regional Climate Data - For many regions of the US and the globe, updated weekly
  from the National Weather Service Climate Prediction Center
• Monitoring climate information - Degree days, Palmer drought data, snow cover data, etc.
  from the National Weather Service Climate Prediction Center
• Pacific Island Climate Data and Maps
  from the National Weather Service Climate Prediction Center
• ​Global Climate Data & Maps - Climate, Weather Analyses and Weather Forecasts
  from the National Weather Service Climate Prediction Center
• Monthly atmospheric and sea surface temprature indices (including SOI)
  from the National Weather Service Climate Prediction Center

Data Products & Analyses

• Upper ocean heat content and ENSO
  from NOAA PMEL Global Tropical Moored Buoy Array
• National Hurricane Center SST analysis
  from the NOAA National Hurricane Center and Central Pacific Hurricane Center
• NCEP Global SST (Near-real time)
  from University of Wisconsin-Madison's Space Science and Engineering Center
• Weekly El Nino/Southern Oscillation (ENSO) Update
  from the National Weather Service Climate Prediction Center
• Current state of the Tropical Pacific & Comparison of different El Niños & United States Climate Interactive pages by state
  from NOAA's Physical Sciences Laboratory
• NOAA WAVEWATCH
  from NOAA NWS Office of Modeling and Development (OMD)

Satellite Data

• Sea surface temperature charts for Equatorial Pacific, Global, etc.
  from the NOAA NESDIS Office of Satellite and Product Operations
• Coral Bleaching Products
  from NOAA/NESDIS/Office of Satellite Data Processing and Distribution
• Near-real time sea level / altimeter data products
  from NOAA/NESDIS Laboratory for Satellite Altimetry
• Sea Surface Temperature Watch on the US West Coast
  from NOAA Coast Watch
• Sea surface temperature data
  from NOAA Office of Satellite & Product Operations

Other Buoy Data

• Equatorial Pacific El Nino (TAO) buoys (NOAA PMEL)
• Interactive marine observations from the National Data Buoy Center (NDBC)
• Tsunami Warning Buoy data (NDBC)
• U.S. Marine Environmental Buoy database from the National Ocean Data Center (NCEI)
• Moored, C-MAN and Drifting buoy data from the National Data Buoy Center (NDBC)
• Tides and Currents (NOAA NOS)
• Global drifting buoys (NOAA AOML)
• Argo profiling floats (NOAA PMEL)

Graphic shows realtime global SST from Space Science and Engineering Center at the University of Wisconsin-Madison.