The model forecasts have become increasingly bullish on a super strong El Niño as each new month has come in – and as we have firmly moved out of the "spring predictability barrier" that makes forecasting historically challenging earlier in the year.

If we instead look at the new relative oceanic niño index (RONI) that subtracts out warming across the tropical oceans, 11 of 14 models predict a record strong 2026/2027 El Niño event, with odds of a record sitting around 77%.

Currently 13 out of 14 dynamical models expect a record setting event based on the Niño 3.4 region sea surface temperature anomalies (ONI), with overall odds of a record sitting at 91% across all 667 model ensemble members.

The 2026/2027 El Niño event has already grown faster than any prior events (at least on an ONI basis). Here its observed and projected future evolution compared to the strongest prior El Niño events in recorded history.

With all the July model runs now in, it is very likely that 2026 will see the largest El Niño event since records began in the late 1800s – and potentially by a truly mind-blowing margin. The median estimate is now 3.6C, roughly 0.8C hotter than the prior record (2.75C). www.theclimatebrink....

My current prediction for 2026 global temperatures (using ERA5) is 1.58C, but year-to-date temperatures are only 1.45C: dashboard.theclimate... This seems like a bit gap, so I thought I'd look at how big a gap there is between year to date and final annual values in past years:

Here is a variant showing the number of 0.1 degree grid cells per year where tmax is over 30C by country over time:

3D is generally not great. But here are individual plots:

Why is AC so rare in much of Europe? Well, until recently it simply wasn't hot enough to need it. Here is the average number of days above 30C (86F) for major cities over time:

However, this is also the period of greatest disagreement in the actual observations; the rate of warming between 1900 and 1945 varies by a factor of two depending on which dataset you look at!

This revealed that human emissions are responsible for about a quarter of the warming during that period, natural factors are responsible for a quarter (both increased solar activity and a set of strong volcanic eruptions after 1900), and multidecadal ocean variability for about half:

I ran a set of 841 climate model simulations looking at what each factor in isolation – CO2, methane, solar forcing, volcanic activity, etc. – would have caused, and how the sum of all these factors compares to observed warming:

Folks skeptical of human-driven warming like to point to a period of somewhat less rapid warming from 1900-1945. In a new analysis at TCB, I dig into the different factors driving it, and find that humans, natural factors, and variability all played an important role: www.theclimatebrink....

The most recent update I did was at the end of May, when I also compared my results to the (at the time) just-released WMO 5-year forecast. I'll do another update when all the June observational records are in.

The global surface temperature record is one of the most iconic figures in climate science. We now have 12 different groups of researchers from the US, UK, EU, Japan, and China (among others) that have calculated it and found nearly identical results:

Fascinating report by Lily Bermal that despite the Trump admin's efforts more than half of carbon reductions under the IRA remain intact, at least for the power sector. This is in part due to continuing cost-competitiveness of solar and wind post-subsidies ceepr.mit.edu/workin...

All the ENSO forecasts are baked into 2026 projections. It still seems pretty unlikely (<15% chance) that we see a new record this year.

Interestingly, ECMWF has ENSO3.4 regions continuing to warm through December, while NOAA's CFSv2 has El Niño peaking in November. It will be interesting to see what other models July runs show as they are released in the coming days.

If we look at RONI – which differences tropical sea surface temperatures from the ENSO3.4 region temperatures – we see an event reaching 3.3C in December, and are about 0.2C warmer than the June forecasts.

July ECMWF runs are in and forecast an even more extreme El Niño event than the prior June runs. ENSO3.4 region temperatures reach 3.9C in December, and forecasts are around 0.3C warmer than they were in June.

Human emissions of aerosols like SO2 can serve as cloud condensation nuclei and increase low reflective cloud cover. Cleaning up air pollution reduces reflectivity and lets more light through. But thats unmasking additional GHG forcing, not solar forcing: www.carbonbrief.org/explainer-ho...

This is a pretty generous approach to attributing temperature to solar forcing, as it uses an instantaneous equilibrium response of 0.5 to 1.2C for each w/m^2 increase in forcing (equivalent to a climate sensitivity of 2.0 to 4.7C). Using a proper climate model gives a somewhat smaller response:

On this hot fourth of July it is worth reminding folks that its not the sun that's causing global warming. Solar output (as measured by satellites) has been flat over the past 50 years when global temperatures have shot up. Its our emissions of CO2 and other greenhouse gases.

June 2026 was the second warmest June on record (after 2024) in the ERA5 dataset, at 1.39C above preindustrial levels. While we expect warmer temperatures later this year as El Niño kicks in, 2026 is now increasingly likely (~86% chance) to be the second warmest year on record.

And the climate model/observation comparison tab:

Here is what the updated ENSO tab looks like:

I used the newly (re)released Fable 5 release to give my Climate Dashboard a major design improvement – and add a bunch of new features in the process. Check it out at: dashboard.theclimate...

CFSv2 is historically pretty near the middle of the pack, I believe. But it varies a bit over time. There is still a pretty wide range across models but everyone has been trending upward over time...

When I originally made this chart back in April I only colored El Nino from 0.5C to 4C, because who could imagine 3.4 anomalies above 4C... Also here is RONI:

Go home CFSv2, you're drunk. 😳