<\/p>\n Conditions for this phase briefly developed last winter<\/a>, but they didn’t stick around long enough to be considered an official La Ni\u00f1a event in the historical record. The latest ENSO forecast<\/a> from the National Weather Service indicated that we could be in for something similar in the coming months.<\/p>\n You may like<\/p>\n A period of La Ni\u00f1a conditions is favored for the fall and early winter, and there’s a 21% chance that the current July-to-September period will qualify. The likelihood then rises to more than 50% for overlapping 3-month periods between September and January. Still, forecasters aren’t expecting massive weather shifts.<\/p>\n “If La Ni\u00f1a forms, it’s likely to be weak, meaning La Ni\u00f1a wouldn’t exert a strong influence over the winter,” Emily Becker<\/a>, a research professor at the University of Miami and lead writer of the National Oceanic and Atmospheric Administration’s ENSO blog<\/a>, told Live Science in an email.<\/p>\n Related: <\/strong>Watch Hurricane Erin reach Category 5 strength in a blaze of lightning<\/strong><\/a><\/p>\n The ENSO cycle triggers a warm El Ni\u00f1o phase and then a cold La Ni\u00f1a phase every two to seven years, on average, with each phase lasting around nine to 12 months. However, the timing of these phases varies, and they’re difficult to predict.<\/p>\n The phases are defined by changes in the sea surface temperature of the Ni\u00f1o region of the east-central Pacific and a shift in atmospheric conditions, which impact the Pacific jet stream. El Ni\u00f1o conditions occur when the sea surface temperature is 0.9 degrees Fahrenheit (0.5 degrees Celsius) higher than the long-term average, while La Ni\u00f1a conditions happen when the sea surface temperature falls 0.9 F below the long-term average.<\/p>\n We were due to enter a La Ni\u00f1a last summer, but the conditions didn’t develop until December. That delayed start meant that La Ni\u00f1a didn’t have time to gain strength before the onset of winter.<\/p>\n NOAA has a flowchart for declaring La Ni\u00f1a. (Image credit: NOAA Climate.gov)<\/p>\n Last year’s warmer-than-average ocean temperatures might have played a role in the delay. Earth was in an El Ni\u00f1o between May 2023 and March 2024, which contributed to record-breaking heat<\/a> during that period. However, the planet has continued to warm with climate change<\/a>, regardless of what ENSO is doing<\/a>.<\/p>\n![\"NOAA](\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2025\/08\/QSR7uUjYYiUg8VFuYaQGxT.jpg\")
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