Higher warming predictions for 2026 and 2027 – Image for illustrative purposes only (Image credits: Unsplash)
Early data from the first quarter of 2026 already show temperatures running warmer than many expected at the start of the year. At the same time, forecasts for a strong El Niño in the tropical Pacific have firmed up, prompting researchers to lift their projections for both 2026 and 2027. The revisions remain modest in absolute terms, yet they shift the odds noticeably toward new record highs.
Why the Numbers Moved Higher
At the end of last year, simple statistical models placed 2026 at roughly 1.41 degrees Celsius above the pre-industrial baseline. The same models now point to 1.46 degrees Celsius, with a likely range of 1.36 to 1.59 degrees. For 2027 the central estimate rose from 1.57 to 1.61 degrees Celsius, and the upper bound of the uncertainty range climbed to 1.93 degrees.
The main driver is the emerging El Niño. Latest multi-model runs place the peak sea-surface temperature anomaly in the Niño 3.4 region at about 2.7 degrees Celsius, comparable to the powerful 2015-2016 event. Because El Niño typically adds warmth to global temperatures with a lag of several months, the influence is expected to stretch into 2027 as well.
How the Updated Models Work
The new calculations rely on regression equations that incorporate several observed and predicted factors at once. For 2026 these include the year-to-date temperature anomaly, the most recent monthly value, the observed El Niño state so far, and the forecasted state through the rest of the year. Uncertainty in the El Niño forecast is sampled repeatedly with a Monte Carlo approach to produce the final range.
The 2027 projection builds directly on the 2026 estimate. It adds the long-term warming trend of roughly 0.026 degrees Celsius per year and then layers on the expected boost from the developing El Niño during its peak months of September through December. The same Monte Carlo sampling propagates uncertainty from both the 2026 starting point and the El Niño forecast, widening the error bars slightly compared with earlier, simpler methods.
Tests against past strong El Niño years show the approach performs reasonably well. It slightly under-predicted the temperature jumps in 1973, 1983, and 1998, matched 2016 closely, and slightly over-predicted the rise from 2023 to 2024. These historical checks give some that the current upward revision is not an outlier.
Chances of New Records
Even with the higher central estimate, 2026 is still more likely than not to finish as the second-warmest year on record, carrying roughly a 56 percent probability. There remains a 26 percent chance it becomes the warmest year yet measured and a 34 percent chance it exceeds the 1.5-degree threshold. The picture for 2027 is more decisive: an 85 percent likelihood of setting a new record and an 88 percent chance of surpassing 1.5 degrees Celsius.
These probabilities sit somewhat below the most recent estimate from James Hansen and colleagues, who place 2026 at 1.7 degrees Celsius. The difference largely reflects varying assumptions about how strongly the current El Niño will translate into global surface temperatures.
What Remains Uncertain
Forecasts issued in spring still face the well-known “spring predictability barrier,” when El Niño models have historically shown lower skill. A fresh set of runs from the Canadian climate model CanSIPS arrived this week with higher values than earlier versions, trimming the lower end of the uncertainty range without shifting the overall median. Further updates through the summer could still move the numbers.
Additional factors such as volcanic activity, changes in aerosol emissions, or unexpected shifts in ocean heat uptake could also alter the outcome. The models already include the long-term acceleration of warming, yet they cannot capture every short-term influence that may appear in the coming months.
Key points to watch
- 2026 central estimate now 1.46 °C (range 1.36–1.59 °C)
- 2027 central estimate now 1.61 °C (range 1.40–1.93 °C)
- Strong El Niño peak of ~2.7 °C expected in late 2026
- 2027 carries an 85 % chance of becoming the warmest year on record
These revised outlooks underscore how sensitive near-term temperature records remain to the strength and timing of El Niño events. As more data arrive, the picture for the next two years will sharpen, but the direction of travel is already clear: the coming years are likely to test the upper end of recent warming trends.
