Tropical Pacific water temperatures are shockingly hot. Last week equatorial Pacific water temperatures averaged 3 degrees Celsius above normal for the first time ever in the key Niño 3.4 region. The previous weekly high Niño 3.4 value of 2.8 degrees was tied last week with Nov. 28, 1997. The Niño 3.4 region, used to measure the strength of an El Niño ranges from 170W to 120W from 5 degrees north to 5 degrees south of the equator. If temperatures continue to rise, or plateau for a few more weeks, this will be the strongest El Niño in history.