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 TAO buoy network
• State of the ocean climate - ENSO indices | Atmosphere | Surface ocean | subsurface ocean | sea ice
  from NOAA Ocean Observations Panel for Climage
• Global drifting buoys 
  from NOAA AOML
• Argo profiling floats
  from NOAA PMEL, the U.S. Argo Data Center, the Argo Information Centre, 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 Cooperative Agency Profilers (CAP) profiler data (vertical profiles of hourly winds)
  from NOAA Earth System Research Laboratory
• Realtime SST data
  from NOAA National Centers for Environmental Prediction
• Realtime climate maps | US Climate plotting | Sea Surface Temperature animations  
• from NOAA ESRL
• Regional Climate Data - For many regions of the US and the globe, updated weekly
  from the Climate Prediction Center at the National Centers for Environmental Prediction 
• Monitoring climate information - Degree days, Palmer drought data, snow cover data, etc.
  from the National Centers for Environmental Prediction / Climate Prediction Center
• Pacific Island Climate Data and Maps
  from the National Centers for Environmental Prediction / Climate Prediction Center
• ​Global Climate Data & Maps - Climate, Weather Analyses and Weather Forecasts
  from the Climate Prediction Center at the National Centers for Enviornmental Prediction
• Monthly atmospheric and sea surface temprature indices (including SOI)
  from the National Centers for Environmental Prediction / Climate Prediction Center

Data Products & Analyses

• Upper ocean heat content and ENSO
  from NOAA PMEL TAO
• NCEP Sea Surface Temperature: Global | Tropical Pacific
  from Sea Surface Temperature analyses page at NCEP's Environmental Modeling Center
• Recent BMRC/NMC Global SST analyses
  from the Ocean Analyses page at the Bureau of Meteorology Research Center in Australia
• NCEP Global SST
  from University of Wisconsin-Madison's Space Science and Engineering Center
• Global Sea Surface Temperature Charts: Temperature, Anomaly & Climatology
  from the Navy Coupled Ocean Data Assimilation (NCODA) at the United States Navy Fleet Numerical Meteorology and Oceanography Center
• OSCAR Ocean Surface Current Analyses
  from satellite data analyses by NOAA's OSCAR project
• Weekly El Nino/Southern Oscillation (ENSO) Update
  from the National Centers for Environmental Prediction / Climate Prediction Center
• Current state of the Tropical Pacific & Comparison of different El Niños & United States Climate Interactive pages by state
  from NOAA's Earth system Research Laboratory
• NOAA Wave Watch
  from NOAA Environmental Modeling Center
   

Satellite Data

• Sea surface temperature charts for Equatorial Pacific, Global, etc.
  from the NOAA/NESDIS/Office of Satellite Data Processing and Distribution
• 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
• Near real-time satellite altimetry data
  from Colorado Center For Astrodynamics Research
• Sea Surface Temperature Watch on the US West Coast
  from NOAA Coast Watch

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 (NODC)
• Moored, C-MAN and Drifting buoy data from the National Data Buoy Center (NDBC)
• Tides and Currents (NOAA NOS)
• Tides Online (NOAA NOS)
• Global drifting buoys (NOAA AOML)
• Argo profiling floats (NOAA PMEL)

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