(Roughly) Daily

Climatologist Zeke Hausfather on what’s turning out to be a scorching summer…

I’m generally pretty measured in how I discuss climate data. There has been only one time in recent years when I was truly shocked: when global temperatures came in for September 2023 at a full 0.5C warmer than any prior September on record. Once until today, that is. With the July runs now in from 667 ensemble members across 14 different seasonal forecast models, it looks like this year’s El Niño is not only very likely to be the strongest event since reliable records began – it may end up the strongest by a truly mind-blowing margin.

The multi-model median for the event’s peak (measured as detrended sea surface temperature anomalies in the Niño 3.4 region of the tropical Pacific) currently stands at 3.6C, roughly 0.8C hotter than the prior record of 2.75C set in 2015-16. For context, the gap between the strongest and the fifth strongest El Niño of the past 150 years is only about 0.5C. The models are forecasting something outside the envelope of anything we have ever observed [as the chart at the top illustrates].

A few things stand out in this figure. First, no event in a century and a half of observations has ever pushed meaningfully past 2.75C. The legendary 1877-78 event comes closest, in a statistical dead heat with 2015-16 (2.73C vs 2.75C, well within the uncertainty of 19th-century ship data). Second, the middle 80% of this year’s forecast ensemble sits entirely at or above that all-time record: even the low end of the plume (2.8C) grazes it. Around 91% of ensemble members exceed the 2015-16 record at their peak…

… What is remarkable here is not just the level but the trajectory. The 2026 event is developing faster than 1997-98, the previous gold standard for explosive El Niño onsets. And unlike 2015 which started its year already warm from a precursor event, this one launched from genuinely La Niña-ish conditions in January…

Read on the for the chilling-but-in-the-wrong-way details.

A ~90% chance of a record-setting event: “The Strongest El Niño Ever,” from @zekehausfather.com.

More detail– and opportunity to track the heat– at Zeke’s Climate Dashboard. And for related info, see also Climate.us— the volunteer-fielded “successor” to the now-suppressed Climate.gov.

Apposite: “Staying Cool: Helpful Hints From History- a look back at how others have survived—and thought about—the high heat of summer.”

* Jane Austen, in a 1796 letter to her elder sister, Casandra

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As we sweat it, we might send scorching birthday greetings to the sublime Martha Reeves; she was born on this date in 1941. A singer, she is best known for her work in Martha and the Vandellas, which scored several major Hot 100 hits, including “Nowhere to Run,” “Jimmy Mack,” “Dancing in the Street,” and of course, “Heat Wave.” In 1995, the group was inducted into the Rock and Roll Hall of Fame; in 2023, Reeves was included on Rolling Stone‘s list of the 200 Greatest Singers of All Time.