Not only was August 2026 the warmest August on record, it was also the planet's *moistest month* on record, surpassing July 2024. As Earth has warmed, the level of water vapor in the atmosphere has risen, a trend that has grown steeper in recent years. Water vapor is itself a powerful greenhouse gas, so that added moisture reinforces the initial warming — creating a feedback loop between rising temperatures and a moister atmosphere. Now, with the strongest El Niño on record soon expected, moisture levels will probably blast past previous records well into 2027. And although the level of moisture in the sky doesn’t have a one-to-one relationship with rainfall amounts, having more moisture can boost the odds for rainfall extremes, if there’s a force to squeeze that moisture out. For example, during August, 17 percent of the planet experienced monthly precipitation that was in the top 10 percent of historical August totals — the most widespread coverage of upper-decile rainfall during August considering records back to 1940. While having the potential for more rain could create opportunities in some places, for many others, this will likely elevate the risks for dangerous extremes and flooding that infrastructure may struggle to cope with. Large swaths of the planet will probably soon feel the effects of this trend firsthand, with odds favoring an unusually stormy and wet winter across much of the United States, Europe and eastern Asia, as well as South America. This moistening trend is a globally important one, and it's going to be a wild ride over the next year.

The Niño 1+2 Index near Peru and Ecuador has reached a remarkable, record-breaking 4.8°C above average, surpassing the record from 1983. Ocean temperatures are forecast to surge toward 6°C above average during October. There is no modern precedent for these conditions.