[AaronInCarolina]

Hard to tell. 2006 started with a weak La Nina condition, switched to a mild (and shorter than expected) El Nino from about May-September, and ended just about in a normal condition.

Your assessment of the most recent El Nino is a little off in your dates. There was no El Nino activity in the May-September time frame. It didn't start cranking up until about October, and lasted until around February of this year. See Operational SST Anomaly Charts for the year 2006 for yourself.

[cogitator]

You're right, I misread my source. This is what I was reading, from the NCDC climate of 2006 summary.

"The year began with ENSO in a weak cold phase (La Niña) which had developed during late 2005, and the presence of these La Niña conditions in the equatorial Pacific contributed to the lower global average temperature this year. By April and May 2006, the near-equatorial SST anomalies had warmed to near-normal in the central Pacific region as the ENSO transitioned to a neutral phase. El Niño conditions developed in September, and by the end of December, sea surface temperatures in most of the central and eastern equatorial Pacific were more than 1.0°C (1.8°F) above average."

Thank you for the correction.