尽管时序已进入秋季，美国大部分地区依然持续笼罩在异常的高温之中。受到圣婴现象与气候变迁的双重影响，美国气候预测中心预估高温偏热的天气将至少持续至九月底，其中上中西部与深南部地区的气温可能比往常高出华氏5至10度，打破了许多长达一世纪以上的历史纪录。

气候变迁是导致这波全美极端热浪的核心推手，它垫高了气温的基准线，使得夜间降温幅度严重不足，大幅加剧了人体承受的热压力与健康风险。同时，气候暖化亦助长了强烈的高压脊与「热穹顶」现象，沉降的高压气流经压缩后加温，配合强烈日照与干燥土壤，进一步放大了高温的破坏力。

展望未来几个月，虽然秋末的极端高温程度难以与七月盛夏相比，但在强烈圣婴现象对急流与全球天气型态的持续干扰下，异常温暖的海洋将促使全美广泛区域在秋冬两季继续维持高于平均水平的偏暖气候，这意味著打破高温纪录的情势短期内恐难完全平息。

Despite the calendar turning to autumn, unseasonably hot weather continues to grip much of the United States. Driven by the combined effects of El Niño and climate change, the US Climate Prediction Center forecasts that above-normal temperatures will persist at least through the end of September, with regions in the Upper Midwest and Deep South potentially experiencing temperatures 5 to 10 degrees Fahrenheit higher than normal after an unprecedented summer of broken records.

Climate change serves as the primary catalyst behind this nationwide extreme heat by raising the baseline temperature, which leads to dangerously high overnight temperatures that deny people critical nighttime relief and severely increase heat-stress risks. Additionally, a warming planet facilitates stronger atmospheric high-pressure ridges known as heat domes, where sinking and compressing air collides with intense sunlight and dry ground to drive heat levels well above historic norms.

Looking forward, while temperature extremes through late September may not reach midsummer peaks, persistent summer-like conditions are expected to endure as a potentially record-setting El Niño continues to alter the jet stream and seasonal patterns. Historical analogues of strong El Niño events indicate that a vast portion of the nation will likely face warmer-than-normal conditions through the fall and winter, suggesting more high-temperature records could still fall.