We observe a net loss of 3.2 (±1.1) × 1022 J of heat from the upper ocean between 2003 and 2005. Using a broad array of in situ ocean measurements, we present annual estimates of global upper‐ocean heat content anomaly from 1993 through 2005. Including the recent downturn, the average warming rate for the entire 13‐year period is 0.33 ± 0.23 W/m2 (of the Earth's total surface area). A new estimate of sampling error in the heat content record suggests that both the recent and previous global cooling events are significant and unlikely to be artifacts of inadequate ocean sampling.