January weather in Union City, CA
The average temperature in Union City in January is 50.6°F (42.6°F–58.6°F). Average precipitation: 3.00 inches.
January is a winter month in Union City, and is cooler than the annual average of 59.5°F. Daily temperatures swing about 16°F between overnight low and afternoon high. Expect about 10 days with precipitation. Daylight averages about 9h 40m. For travel, January is a comfortable month to visit.
Avg High
58.6°F
Avg Low
42.6°F
Precipitation
3.00 in
Daylight
9h 40m
January records in Union City
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| January 1 | 68.0°F (2012) | 32.0°F (2022) | 1.01 in (2004) |
| January 2 | 66.9°F (1999) | 28.9°F (2022) | 1.37 in (2006) |
| January 3 | 66.9°F (1999) | 32.0°F (2004) | 0.51 in (2024) |
| January 4 | 68.0°F (2018) | 28.0°F (2009) | 1.20 in (2026) |
| January 5 | 66.9°F (2014) | 34.0°F (1999) | 1.27 in (2023) |
| January 6 | 66.0°F (2003) | 33.1°F (2007) | 0.58 in (2019) |
| January 7 | 69.1°F (2015) | 30.0°F (2024) | 0.45 in (2019) |
| January 8 | 69.1°F (2004) | 32.0°F (2024) | 1.32 in (2018) |
| January 9 | 66.9°F (2025) | 36.0°F (1999) | 1.18 in (2023) |
| January 10 | 66.9°F (2025) | 33.1°F (2026) | 0.67 in (2017) |
| January 11 | 64.9°F (2009) | 30.9°F (2013) | 0.62 in (2005) |
| January 12 | 71.1°F (2009) | 30.0°F (2007) | 1.10 in (1998) |
| January 13 | 71.1°F (2009) | 26.1°F (2007) | 0.35 in (2023) |
| January 14 | 71.1°F (2014) | 28.9°F (2007) | 0.82 in (2023) |
| January 15 | 73.0°F (2014) | 27.0°F (2007) | 0.51 in (1998) |
| January 16 | 73.9°F (2014) | 27.0°F (2007) | 1.33 in (2023) |
| January 17 | 72.0°F (2021) | 30.0°F (2012) | 0.97 in (2019) |
| January 18 | 73.9°F (2021) | 30.9°F (2007) | 1.15 in (2016) |
| January 19 | 72.0°F (2021) | 33.1°F (2007) | 0.90 in (2010) |
| January 20 | 71.1°F (2009) | 32.0°F (2023) | 1.20 in (2010) |
| January 21 | 66.9°F (2009) | 30.0°F (2023) | 0.85 in (2012) |
| January 22 | 70.0°F (2011) | 32.0°F (2025) | 1.42 in (2024) |
| January 23 | 69.1°F (2011) | 33.1°F (2002) | 0.76 in (2000) |
| January 24 | 71.1°F (2015) | 33.1°F (1999) | 2.10 in (2000) |
| January 25 | 71.1°F (2014) | 36.0°F (2017) | 0.89 in (1997) |
| January 26 | 70.0°F (2014) | 30.0°F (2021) | 0.70 in (1997) |
| January 27 | 71.1°F (2015) | 30.9°F (2025) | 0.84 in (2021) |
| January 28 | 71.1°F (2015) | 32.0°F (1999) | 1.42 in (2021) |
| January 29 | 69.1°F (2024) | 35.1°F (1999) | 0.97 in (1998) |
| January 30 | 66.9°F (2024) | 30.9°F (2002) | 0.46 in (2011) |
| January 31 | 73.0°F (2015) | 32.0°F (2023) | 0.56 in (1999) |