August weather in Union City, CA
The average temperature in Union City in August is 67.7°F (57.1°F–78.2°F). Average precipitation: 0.02 inches.
August is a summer month in Union City, and is warmer than the annual average of 59.5°F. Daily temperatures swing about 21.1°F between overnight low and afternoon high. Expect about 0 days with precipitation. Daylight averages about 13h 27m. For travel, August is one of the best months of the year to visit.
Avg High
78.2°F
Avg Low
57.1°F
Precipitation
0.02 in
Daylight
13h 27m
August records in Union City
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| August 1 | 90.0°F (1998) | 53.1°F (2010) | 0.00 in (1996) |
| August 2 | 93.9°F (1998) | 53.1°F (2018) | 0.00 in (1996) |
| August 3 | 100.9°F (1998) | 52.0°F (2025) | 0.00 in (1996) |
| August 4 | 102.0°F (1998) | 52.0°F (2025) | 0.00 in (1996) |
| August 5 | 91.9°F (1997) | 52.0°F (2025) | 0.00 in (1996) |
| August 6 | 91.0°F (1997) | 53.1°F (2002) | 0.00 in (1996) |
| August 7 | 91.0°F (1997) | 52.0°F (2002) | 0.01 in (2015) |
| August 8 | 93.0°F (2002) | 54.0°F (1996) | 0.00 in (1996) |
| August 9 | 97.0°F (2002) | 53.1°F (1998) | 0.00 in (1996) |
| August 10 | 93.9°F (2002) | 46.0°F (2005) | 0.00 in (1996) |
| August 11 | 93.0°F (1998) | 53.1°F (2012) | 0.00 in (1996) |
| August 12 | 96.1°F (1996) | 54.0°F (2007) | 0.00 in (1996) |
| August 13 | 91.0°F (1998) | 52.0°F (2022) | 0.00 in (1996) |
| August 14 | 97.0°F (2020) | 52.0°F (2022) | 0.00 in (1996) |
| August 15 | 98.1°F (2019) | 52.0°F (2010) | 0.00 in (1996) |
| August 16 | 97.0°F (2015) | 54.0°F (1996) | 0.01 in (2020) |
| August 17 | 91.0°F (2015) | 52.0°F (2006) | 0.00 in (1996) |
| August 18 | 91.0°F (2020) | 53.1°F (1996) | 0.00 in (1996) |
| August 19 | 84.9°F (2020) | 53.1°F (1996) | 0.01 in (1997) |
| August 20 | 88.0°F (2025) | 51.1°F (1996) | 0.44 in (1997) |
| August 21 | 90.0°F (2025) | 53.1°F (1998) | 0.00 in (1996) |
| August 22 | 86.0°F (1996) | 53.1°F (1998) | 0.00 in (1996) |
| August 23 | 90.0°F (2010) | 53.1°F (1998) | 0.00 in (1996) |
| August 24 | 99.0°F (2010) | 52.0°F (1998) | 0.00 in (1996) |
| August 25 | 99.0°F (2010) | 52.0°F (1998) | 0.00 in (1996) |
| August 26 | 90.0°F (2017) | 51.1°F (1998) | 0.00 in (1996) |
| August 27 | 91.9°F (2002) | 53.1°F (2005) | 0.00 in (1996) |
| August 28 | 96.1°F (2009) | 50.0°F (1998) | 0.00 in (1996) |
| August 29 | 95.0°F (2008) | 52.0°F (2010) | 0.01 in (2000) |
| August 30 | 91.0°F (2025) | 52.0°F (2006) | 0.01 in (2000) |
| August 31 | 93.0°F (2005) | 52.0°F (1998) | 0.00 in (1996) |