“The Niño3.4 SST anomaly index is an indicator of central tropical Pacific El Niño conditions. It is calculated with SSTs in the box 170°W – 120°W, 5°S – 5°N.” NOAA -State of the Ocean Climate
NOAA’s weekly data file since January, 1990 is here.
Nino3.4 continues to increase, indicating that we are heading for an El Nino event. The impact of an El Nino can be significant to global temperatures, 1998 for example. It is to early to tell whether 2014 will see a significant El Nino like 1998 or just a minor event.