Siena Weather in August
Average highs run from 33°C on August 1 to 29°C on August 31, and lows from 19°C to 16°C. Normal precipitation for the month is 34 mm over about 6 wet days.
August day by day
The normal high and low for each date, in °C.
- Normal low
- Normal high
- Reanalysis extreme high
- Reanalysis extreme low
August at a glance
- Average high
- 32°C
- Average low
- 18°C
- Precipitation
- 34 mm
- Reanalysis high
- 41°CAug 1, 2017
- Reanalysis low
- 10°CAug 29, 1995
- Daylight
- 14 h 32 min to 13 h 15 min
- Cloud cover
- 39%
- Humidity
- 56%
- Dew point
- 14°C
- Wind
- 9.4 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 |
|---|---|---|---|---|---|
| Aug 1 | 33°C | 19°C | 41°C 2017 | 14°C 2010 | 19% |
| Aug 2 | 33°C | 19°C | 39°C 2017 | 15°C 2007 | 19% |
| Aug 3 | 33°C | 19°C | 39°C 2017 | 16°C 1997 | 19% |
| Aug 4 | 33°C | 19°C | 39°C 2017 | 16°C 2006 | 19% |
| Aug 5 | 33°C | 19°C | 40°C 2017 | 14°C 2006 | 19% |
| Aug 6 | 33°C | 19°C | 39°C 2003 | 14°C 2000 | 19% |
| Aug 7 | 33°C | 19°C | 38°C 2015 | 15°C 2000 | 19% |
| Aug 8 | 33°C | 19°C | 38°C 2015 | 14°C 2005 | 19% |
| Aug 9 | 32°C | 19°C | 38°C 2003 | 13°C 2005 | 19% |
| Aug 10 | 32°C | 18°C | 38°C 2003 | 13°C 2007 | 18% |
| Aug 11 | 32°C | 18°C | 39°C 1998 | 14°C 2011 | 18% |
| Aug 12 | 32°C | 18°C | 38°C 1998 | 13°C 2016 | 17% |
| Aug 13 | 32°C | 18°C | 38°C 2003 | 13°C 2001 | 17% |
| Aug 14 | 32°C | 18°C | 36°C 1993 | 13°C 2006 | 17% |
| Aug 15 | 32°C | 18°C | 36°C 2001 | 14°C 2006 | 17% |
| Aug 16 | 32°C | 18°C | 36°C 2001 | 13°C 2005 | 16% |
| Aug 17 | 32°C | 18°C | 37°C 1993 | 11°C 2014 | 16% |
| Aug 18 | 32°C | 18°C | 37°C 2012 | 13°C 2014 | 16% |
| Aug 19 | 32°C | 18°C | 38°C 2012 | 14°C 2014 | 16% |
| Aug 20 | 32°C | 18°C | 39°C 2012 | 14°C 1995 | 16% |
| Aug 21 | 32°C | 18°C | 39°C 2011 | 13°C 2007 | 16% |
| Aug 22 | 32°C | 18°C | 38°C 2011 | 13°C 2005 | 16% |
| Aug 23 | 31°C | 18°C | 38°C 2011 | 14°C 2005 | 16% |
| Aug 24 | 31°C | 18°C | 37°C 2011 | 14°C 2007 | 18% |
| Aug 25 | 31°C | 17°C | 37°C 2011 | 16°C 2008 | 19% |
| Aug 26 | 31°C | 17°C | 38°C 2000 | 14°C 2014 | 20% |
| Aug 27 | 31°C | 17°C | 37°C 2017 | 12°C 2018 | 21% |
| Aug 28 | 30°C | 17°C | 35°C 1992 | 11°C 1995 | 23% |
| Aug 29 | 30°C | 17°C | 35°C 2017 | 10°C 1995 | 24% |
| Aug 30 | 30°C | 16°C | 36°C 2017 | 10°C 1993 | 24% |
| Aug 31 | 29°C | 16°C | 34°C 2015 | 10°C 2010 | 25% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (GMT+2).
- August 1
- sunrise 6:05 AM, sunset 8:37 PM
- August 31
- sunrise 6:37 AM, sunset 7:52 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 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.