September Weather Forecast: Breezy Start with Possible Record Highs

The September temperature outlook for the Lower 48 states in the U.S. predicts above-average temperatures, with the northwestern region trending near average or slightly cooler. The updated forecast indicates that most of the Plains, upper Midwest, East Coast, Rockies, and Southwest will experience warmer than average conditions, while the Northwest and Northern California may be near or slightly cooler than average. The dominant upper-level pattern features a high-pressure ridge over the Midwest and a southward dip in the jet stream near the Northwest, resulting in warmer temperatures for the first week of September. The forecast suggests that the central and eastern U.S. may experience a hotter than average month, resembling the third-warmest September on record.