São Francisco Weather in September
Average highs run from 34°C on September 1 to 35°C on September 30, and lows from 19°C to 21°C. Normal precipitation for the month is 12 mm over about 3 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
- 35°C
- Average low
- 20°C
- Precipitation
- 12 mm
- Reanalysis high
- 40°CSep 29, 2020
- Reanalysis low
- 14°CSep 7, 1991
- Daylight
- 11 h 49 min to 12 h 13 min
- Cloud cover
- 34%
- Humidity
- 41%
- Dew point
- 11°C
- Wind
- 15.1 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 | 34°C | 19°C | 37°C 2014 | 15°C 1997 | 5% |
| Sep 2 | 34°C | 19°C | 37°C 2015 | 15°C 1997 | 4% |
| Sep 3 | 34°C | 19°C | 38°C 2014 | 15°C 1997 | 4% |
| Sep 4 | 34°C | 19°C | 38°C 2015 | 15°C 2004 | 4% |
| Sep 5 | 34°C | 19°C | 39°C 2015 | 15°C 2011 | 4% |
| Sep 6 | 34°C | 19°C | 37°C 2015 | 14°C 1995 | 3% |
| Sep 7 | 34°C | 19°C | 38°C 2015 | 14°C 1991 | 3% |
| Sep 8 | 34°C | 19°C | 38°C 1997 | 14°C 1991 | 4% |
| Sep 9 | 35°C | 19°C | 39°C 1997 | 14°C 2006 | 4% |
| Sep 10 | 35°C | 19°C | 40°C 1997 | 16°C 2006 | 4% |
| Sep 11 | 35°C | 20°C | 39°C 1997 | 16°C 2010 | 4% |
| Sep 12 | 35°C | 20°C | 39°C 2001 | 16°C 2010 | 4% |
| Sep 13 | 35°C | 20°C | 39°C 2012 | 16°C 2010 | 5% |
| Sep 14 | 35°C | 20°C | 38°C 2012 | 16°C 1994 | 5% |
| Sep 15 | 35°C | 20°C | 39°C 1997 | 17°C 2007 | 6% |
| Sep 16 | 35°C | 20°C | 39°C 1997 | 17°C 2007 | 7% |
| Sep 17 | 35°C | 20°C | 38°C 2014 | 16°C 2011 | 7% |
| Sep 18 | 35°C | 20°C | 39°C 1997 | 16°C 2011 | 8% |
| Sep 19 | 35°C | 21°C | 39°C 2019 | 15°C 2011 | 9% |
| Sep 20 | 35°C | 21°C | 39°C 2020 | 15°C 2011 | 10% |
| Sep 21 | 35°C | 21°C | 39°C 2019 | 16°C 2011 | 10% |
| Sep 22 | 35°C | 21°C | 39°C 1998 | 17°C 2011 | 11% |
| Sep 23 | 35°C | 21°C | 39°C 2013 | 17°C 1991 | 13% |
| Sep 24 | 35°C | 21°C | 40°C 2013 | 17°C 2008 | 14% |
| Sep 25 | 35°C | 21°C | 40°C 2015 | 15°C 1999 | 15% |
| Sep 26 | 35°C | 21°C | 40°C 2015 | 16°C 1999 | 16% |
| Sep 27 | 35°C | 21°C | 39°C 2003 | 18°C 2002 | 17% |
| Sep 28 | 35°C | 21°C | 40°C 2015 | 16°C 2006 | 19% |
| Sep 29 | 35°C | 21°C | 40°C 2020 | 16°C 2006 | 20% |
| Sep 30 | 35°C | 21°C | 39°C 2020 | 17°C 2012 | 20% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (GMT-3).
- September 1
- sunrise 6:05 AM, sunset 5:54 PM
- September 30
- sunrise 5:43 AM, sunset 5:56 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.