United States weather in September
United States in September averages 20°C (69°F) and 72 mm of rain.
Of the twelve months in United States, September is the fourth warmest and the fifth wettest.
- Average temp
- 20°C (69°F)
14–27°C · 57–81°F
- Rainfall
- 72 mm
Showers likely
- Sunshine
- —
- Wind
- 16 km/h
What is United States like in September?
Daytime
Days are warm, typically in the mid-20s°C or above.
Rain
Some rain is likely; pack for showers.
Evening
Evenings are cooler. A layer helps after sunset.
What should I pack for United States in September?
A light rain jacket
About 72 mm falls this month — showers rather than washouts.
A layer for the evening
The day swings about 13°C between its low and its high.
September compared with August and October
September in United States is 4.4°C cooler than August and 15 mm drier than it, which averages 25°C (77°F).
September in United States is 7.2°C warmer than October and 22 mm wetter than it, which averages 13°C (56°F).
Daylight in United States in September
On 15 September the sun is up for 12 hours 26 minutes in United States, rising about 07:15 and setting about 19:41 local time.
September ends 1 hour 15 minutes shorter than it begins, so the last week of the month is a different length of day from the first.
That is 2 hours 33 minutes short of June, the longest-lit month here.
Travel guides for United States
What to read before you book.
United States weather by month
TemperatureRainfall
How September compares with the rest of the year
September is highlighted. Every other month links to its own page.
| Month | Average | Rainfall |
|---|---|---|
| January | -2°C / 29°F | 17 mm |
| February | 1°C / 33°F | 20 mm |
| March | 6°C / 44°F | 39 mm |
| April | 12°C / 53°F | 64 mm |
| May | 18°C / 64°F | 112 mm |
| June | 24°C / 74°F | 96 mm |
| July | 26°C / 79°F | 102 mm |
| August | 25°C / 77°F | 88 mm |
| September | 20°C / 69°F | 72 mm |
| October | 13°C / 56°F | 50 mm |
| November | 6°C / 42°F | 29 mm |
| December | 0°C / 32°F | 26 mm |
Similar weather in September
Other destinations whose September averages sit close to this one.
Check another month
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FAQs about United States in September
September climate averages for United States, 1991–2020.
United States averages 20°C (69°F) in September, ranging from about 14°C (57°F) at night to 27°C (81°F) in the afternoon. That is a 1991–2020 average, so an individual week can run either side of it.
Some. About 72 mm falls across September, enough to need a light jacket but not enough to reshape a trip.
Yes. September averages 20°C (69°F) against 13°C (56°F) in October — 7.2°C warmer.
September is 4.4°C cooler than August, and 15 mm drier.
Yes. September falls inside the most comfortable stretch of the year here, May to October, on temperature and rainfall together.
This page does not show today's weather. It is a 1991–2020 climate normal from Meteostat — a long-run average of what September is usually like, which is what you want when booking months ahead. For today or the coming week, check a live forecast.
About 12 hours 26 minutes of daylight in mid-September, against 14 hours 59 minutes in June and 9 hours 22 minutes in December.
On 15 September, sunrise is about 07:15 and sunset about 19:41 local time. Both shift across the month — the month ends 1 hour 15 minutes shorter than it starts.
