The Climate Prediction Center has issued a seasonal outlook indicating a greater than 90 percent likelihood that a very strong El Niño will develop and remain active from the fall of 2026 through the winter of 2026‑2027. Forecasters say the strengthening pattern could bring notable weather effects to the Chicago area during that period.
The outlook is part of the Center's regular assessment of how El Niño conditions may shape North American weather. By evaluating oceanic and atmospheric indicators, the agency gauges the probability that the tropical Pacific warming will intensify and persist. This latest forecast places the probability of a very strong event at a level that exceeds the typical threshold used to signal a high confidence prediction.
A strong El Niño generally influences temperature and precipitation trends across the United States, and the Chicago region can expect deviations from normal patterns when the phenomenon is active. While specific outcomes vary, the presence of a robust El Niño often translates into altered storm tracks and temperature swings that differ from average seasonal expectations.
The forecast covers the upcoming fall and winter months, a time when the Midwest traditionally experiences a range of weather conditions. Residents and local officials are advised to monitor the outlook as it may inform preparation for potential impacts, such as shifts in snowfall amounts or temperature extremes.
The Climate Prediction Center's seasonal outlooks serve as a key resource for weather forecasters, emergency managers, and the public. By communicating the high probability of a very strong El Niño, the Center provides an early indication of the broader climate influences that could shape the region's weather during the latter half of 2026 and into early 2027.