Realtime Climate Data


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Sea Surface Temperature (SST)

Land Surface Temperature

Eq. Pacific Ocean longitude-depth temperature section

Sea-level Pressure (SLP)

  • The Southern Oscillation Index (SOI) is the difference in normalized SLP anomalies for Tahiti and Darwin (Australia) (Tahiti minus Darwin), and it is an indicator of the atmospheric component of the El Niño / Southern Oscillation phenomenon (ENSO). Negative values of the SOI are associated with above normal sea surface temperatures in the equatorial Pacific, and these conditions are commonly called a warm ENSO episode. Positive SOI values are associated with cold Pacific SSTs, and this is called a cold ENSO episode.

500 hPa Geopotential Height Anomalies

Analysis Sources:

Still more analyses can be found at the

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Climate Forecasts

Most of the forecast products are very technical, so non-scientists be warned. Much of the effort in seasonal climate forecasting is expended in forecasting tropical Pacific sea surface temperatures (SSTs), and in particular, how the SSTs in this region vary from one year to the next. These fluctuations are associated with the El Niño / Southern Oscillation phenomenon (ENSO), which the popular press calls El Niño / La Niña.

Global temperature and precipitation forecasts:

Tropical Pacific SST forecasts:

The standard deviation (C) of "Nino3" and "Nino3.4" SST by calendar month (1950-79):
  Jan Feb Mar Apr May June Jul Aug Sep Oct Nov Dec
Nino3 0.93 0.68 0.44 0.53 0.63 0.67 0.75 0.85 0.87 0.89 1.03 1.08
Nino3.4 1.05 0.79 0.59 0.53 0.52 0.53 0.60 0.72 0.80 0.88 1.04 1.06

The standard deviations for other periods>>

Ed Sarachik initiated a very nice WWW page of different forecast products. (This site and the sites it references are without discussion. Scroll down to get to the forecasts. Very technical)

Forecasts of precipitation and air temperatures over land

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Climate Impacts

See also:

Typical ENSO climate impacts

What are the present conditions in the equatorial Pacific?

See latest Pacific Ocean sea surface temperatures (SSTs) and departures from climatology»

The bottom panel indicates regions of above and below normal SST, and conditions on the equator between 180 and 120°W are interpreted in the popular press as "El Niño" (above normal SST, red shading) or "La Niña" (below normal SST, blue shading), respectively. We tend to refer to these variations in the equatorial Pacific SST as warm and cold ENSO episodes, respectively, and we reserve the term "El Niño" to mean the periods of above normal SST along the Peru and Ecuador coast. El Niño and ENSO warm episodes often occur at the same time.

How does the ENSO typically influence the climate in the Pacific Northwest and around the globe?
  1. Impact on the Pacific Northwest of the United States
  2. Global Impacts

The following links are in order of increasing technical difficulty:

A simple description of the primary impacts of warm ENSO episodes on North American climate is presented next. Changes of the climate in the opposite sense are normally observed during cold ENSO episodes.

December through April:
Changes in the preferred regions of storms produce variations in precipitation and surface temperature in the indicated regions: GIF image | PostScript | JPEG.

June through November:
Changes in the number of hurricanes and tropical storms in the Gulf of Mexico, Caribbean Sea, and eastern Pacific. More hurricanes and tropical storms are found in the eastern Pacific and fewer in the Gulf of Mexico and Caribbean Sea during ENSO warm episode years, as shown by the daily storm positions in the left panel. ENSO cold episodes, in contrast, are characterized by fewer Pacific and more Gulf of Mexico and Caribbean Sea storms. ENSO does not seem to affect the number of storms in the main Atlantic basin. GIF image | PostScript | JPEG

Typical temperature and precipitation anomalies during warm ENSO and cold ENSO

Still more information on ENSO is available at:

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Please report problems or corrections to DATA webmaster: Todd Mitchell <>.