January weather in Portola Valley, CA
The average temperature in Portola Valley in January is 47.8°F (40.9°F–54.7°F). Average precipitation: 7.77 inches.
January is a winter month in Portola Valley, and is cooler than the annual average of 57.1°F. Daily temperatures swing about 13.8°F between overnight low and afternoon high. Expect about 14 days with precipitation. Daylight averages about 9h 42m. For travel, January is a wet month.
Avg High
54.7°F
Avg Low
40.9°F
Precipitation
7.77 in
Daylight
9h 42m
January records in Portola Valley
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| January 1 | 64.9°F (1998) | 27.0°F (2016) | 1.92 in (1997) |
| January 2 | 69.1°F (2025) | 32.0°F (2000) | 2.65 in (1997) |
| January 3 | 70.0°F (2001) | 30.0°F (2004) | 1.90 in (2017) |
| January 4 | 71.1°F (2001) | 28.0°F (2009) | 2.04 in (2008) |
| January 5 | 70.0°F (2001) | 28.9°F (2017) | 4.28 in (2008) |
| January 6 | 73.9°F (2015) | 27.0°F (2017) | 2.56 in (2019) |
| January 7 | 75.0°F (2015) | 30.9°F (2024) | 1.61 in (2017) |
| January 8 | 68.0°F (2015) | 33.1°F (2008) | 3.24 in (2017) |
| January 9 | 66.9°F (2003) | 25.0°F (2008) | 2.81 in (2023) |
| January 10 | 64.9°F (2007) | 30.0°F (2011) | 3.17 in (2017) |
| January 11 | 69.1°F (1999) | 28.9°F (2007) | 2.18 in (2001) |
| January 12 | 69.1°F (2002) | 28.0°F (2013) | 3.40 in (1998) |
| January 13 | 75.9°F (2026) | 23.0°F (1997) | 1.84 in (2023) |
| January 14 | 69.1°F (2018) | 21.9°F (1997) | 2.25 in (2023) |
| January 15 | 75.9°F (2026) | 28.9°F (1997) | 1.61 in (1998) |
| January 16 | 73.9°F (2026) | 27.0°F (2012) | 3.32 in (2019) |
| January 17 | 77.0°F (2014) | 27.0°F (2012) | 1.96 in (1996) |
| January 18 | 75.0°F (2026) | 30.0°F (2001) | 1.52 in (1999) |
| January 19 | 73.9°F (2014) | 34.0°F (2002) | 2.59 in (2010) |
| January 20 | 72.0°F (2005) | 32.0°F (2023) | 1.94 in (1999) |
| January 21 | 72.0°F (2005) | 33.1°F (2008) | 3.25 in (2012) |
| January 22 | 68.0°F (2013) | 30.0°F (2002) | 2.04 in (2017) |
| January 23 | 68.0°F (2005) | 28.9°F (2002) | 1.96 in (1997) |
| January 24 | 66.9°F (2011) | 28.0°F (1999) | 4.05 in (2000) |
| January 25 | 75.9°F (2015) | 28.9°F (1999) | 2.26 in (1997) |
| January 26 | 78.1°F (2015) | 28.9°F (2021) | 3.41 in (2008) |
| January 27 | 73.0°F (2015) | 30.0°F (2002) | 1.20 in (1996) |
| January 28 | 72.0°F (2024) | 28.9°F (2002) | 1.89 in (2021) |
| January 29 | 73.0°F (2018) | 27.0°F (2002) | 1.52 in (1998) |
| January 30 | 73.0°F (2026) | 27.0°F (2023) | 1.40 in (2011) |
| January 31 | 73.9°F (2026) | 28.0°F (2002) | 1.79 in (2024) |