The featured chart presents the combination of average September high temperature vs low temperature by year for a statewide averaged value for Iowa. The plot is separated into quadrants based on the averages for each. It is certainly most common to have both values either both above or both below average. The 2026 value is highlighted and while having one of the warmest average low temperatures on record, the average high temperature was not that exceptional. Such was the case this past September with ample cloudiness and elevated humidity preventing overnight cooling and thus buoying low temperatures. Much chillier over night temperatures have already occurred this October as clear skies and lower humidity have allowed temperatures to rapidly cool during the overnight hours.