Osan Weather in September
Average highs run from 26°C on September 1 to 22°C on September 30, and lows from 20°C to 14°C. Normal precipitation for the month is 138 mm over about 9 wet days.
September day by day
The normal high and low for each date, in °C.
- Normal low
- Normal high
- Reanalysis extreme high
- Reanalysis extreme low
September at a glance
- Average high
- 24°C
- Average low
- 17°C
- Precipitation
- 138 mm
- Reanalysis high
- 30°CSep 1, 2015
- Reanalysis low
- 10°CSep 22, 2001
- Daylight
- 12 h 59 min to 11 h 51 min
- Cloud cover
- 62%
- Humidity
- 81%
- Dew point
- 17°C
- Wind
- 12.2 km/h
Every day of the month
A wet day has at least 1 mm of precipitation in the reanalysis.
| Date | Normal high | Normal low | Reanalysis high | Reanalysis low | Chance wet |
|---|---|---|---|---|---|
| Sep 1 | 26°C | 20°C | 30°C 2015 | 15°C 2017 | 45% |
| Sep 2 | 26°C | 20°C | 29°C 2011 | 15°C 2009 | 44% |
| Sep 3 | 26°C | 19°C | 29°C 1994 | 16°C 1993 | 42% |
| Sep 4 | 26°C | 19°C | 29°C 2010 | 14°C 1993 | 41% |
| Sep 5 | 26°C | 19°C | 29°C 2016 | 16°C 2013 | 41% |
| Sep 6 | 26°C | 19°C | 28°C 1992 | 16°C 2006 | 40% |
| Sep 7 | 26°C | 19°C | 28°C 2019 | 16°C 2002 | 38% |
| Sep 8 | 25°C | 19°C | 28°C 2015 | 15°C 2015 | 36% |
| Sep 9 | 25°C | 18°C | 28°C 1998 | 13°C 2015 | 36% |
| Sep 10 | 25°C | 18°C | 29°C 1999 | 14°C 2006 | 35% |
| Sep 11 | 25°C | 18°C | 29°C 2005 | 13°C 2006 | 34% |
| Sep 12 | 25°C | 18°C | 29°C 1998 | 15°C 2006 | 34% |
| Sep 13 | 25°C | 18°C | 29°C 2016 | 14°C 1994 | 34% |
| Sep 14 | 25°C | 17°C | 28°C 2016 | 13°C 1994 | 33% |
| Sep 15 | 24°C | 17°C | 28°C 2016 | 13°C 1994 | 32% |
| Sep 16 | 24°C | 17°C | 28°C 2008 | 13°C 1994 | 32% |
| Sep 17 | 24°C | 17°C | 28°C 2011 | 11°C 1995 | 31% |
| Sep 18 | 24°C | 17°C | 28°C 2008 | 12°C 1995 | 29% |
| Sep 19 | 24°C | 16°C | 28°C 2008 | 12°C 1997 | 28% |
| Sep 20 | 24°C | 16°C | 28°C 2007 | 13°C 2011 | 27% |
| Sep 21 | 24°C | 16°C | 28°C 2015 | 11°C 1997 | 26% |
| Sep 22 | 23°C | 16°C | 29°C 2015 | 10°C 2001 | 26% |
| Sep 23 | 23°C | 16°C | 26°C 2013 | 10°C 2001 | 26% |
| Sep 24 | 23°C | 15°C | 27°C 2015 | 12°C 2011 | 26% |
| Sep 25 | 23°C | 15°C | 28°C 2015 | 12°C 2018 | 26% |
| Sep 26 | 23°C | 15°C | 27°C 2016 | 12°C 2008 | 26% |
| Sep 27 | 22°C | 15°C | 28°C 2015 | 10°C 2008 | 25% |
| Sep 28 | 22°C | 14°C | 29°C 2015 | 12°C 1991 | 24% |
| Sep 29 | 22°C | 14°C | 28°C 2015 | 11°C 2010 | 23% |
| Sep 30 | 22°C | 14°C | 26°C 2019 | 10°C 2010 | 22% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (GMT+9).
- September 1
- sunrise 6:02 AM, sunset 7:01 PM
- September 30
- sunrise 6:26 AM, sunset 6:17 PM
Other months
Sources
Cloud, humidity, wind and sunshine, and temperature and precipitation: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-25. Sun and moon: computed with the NOAA solar equations and Meeus.