The persistent rains and frequent cloudiness this September have greatly reduced chances of early fall season cold weather. For Ames, the minimum season to date low temperature has been just 48°F last Wednesday. The featured chart presents the fall season minimum temperature by year through 30 September. The 2026 value is the warmest on record for the site over this period. Early season cold is certainly dependent on clear skies and dry air allowing efficient overnight cooling. Both of those have been sorely lacking throughout much of September. After we hopefully survive the ongoing deluge of rain this week, there is hope for better weather next as most of the state needs multiple weeks of dry weather to allow fall harvest to begin in earnest.