The highest day temperature in September 2025 was 91°F. The lowest night temperature was 66°F. The average values for day and night temperatures during September were 86.2°F и 69.6°F respectivly.

Almost all days in September are sunny. There is very low probability of clouds or gloomy days.

Precipitation total in September for Bethlehem is 0.1 in. It makes september one of the least rainy months of the year.

The average wind speed in September is 7.1 mph. This value is relatively stable throughout the year.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Bethlehem in September is 11.9 hours.