Napa County Weather in March
Average highs run from 65°F on March 1 to 69°F on March 31, and lows from 43°F to 45°F. Normal precipitation for the month is 4.98 in over about 10 wet days.
March day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
March at a glance
- Average high
- 67°F
- Average low
- 44°F
- Precipitation
- 4.98 in
- Record high
- 87°FMar 20, 2026
- Record low
- 27°FMar 10, 2009
- Chance of a freeze
- 14%
- Daylight
- 11 h 22 min to 12 h 37 min
- Cloud cover
- 54%
- Humidity
- 81%
- Dew point
- 44°F
- Wind
- 6.5 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation.
| Date | Normal high | Normal low | Record high | Record low | Chance wet |
|---|---|---|---|---|---|
| Mar 1 | 65°F | 43°F | 71°F 2013 | 32°F 2001 | 37% |
| Mar 2 | 65°F | 43°F | 73°F 2020 | 30°F 2007 | 36% |
| Mar 3 | 65°F | 43°F | 76°F 2020 | 32°F 2012 | 36% |
| Mar 4 | 65°F | 43°F | 78°F 2020 | 29°F 2018 | 36% |
| Mar 5 | 65°F | 43°F | 72°F 2008 | 28°F 2018 | 36% |
| Mar 6 | 66°F | 43°F | 73°F 2026 | 29°F 2022 | 35% |
| Mar 7 | 66°F | 43°F | 77°F 2026 | 30°F 2003 | 35% |
| Mar 8 | 66°F | 43°F | 80°F 2004 | 28°F 2002 | 35% |
| Mar 9 | 66°F | 44°F | 79°F 2004 | 30°F 2010 | 34% |
| Mar 10 | 66°F | 44°F | 85°F 2004 | 27°F 2009 | 34% |
| Mar 11 | 66°F | 44°F | 82°F 2005 | 31°F 2006 | 34% |
| Mar 12 | 66°F | 44°F | 79°F 2007 | 31°F 2021 | 33% |
| Mar 13 | 66°F | 44°F | 80°F 2017 | 31°F 2006 | 33% |
| Mar 14 | 67°F | 44°F | 80°F 2017 | 30°F 2002 | 33% |
| Mar 15 | 67°F | 44°F | 85°F 2004 | 30°F 2002 | 32% |
| Mar 16 | 67°F | 44°F | 85°F 2004 | 29°F 2021 | 32% |
| Mar 17 | 67°F | 44°F | 85°F 2026 | 33°F 2002 | 31% |
| Mar 18 | 67°F | 44°F | 86°F 2026 | 31°F 2018 | 31% |
| Mar 19 | 67°F | 44°F | 84°F 2026 | 32°F 2002 | 31% |
| Mar 20 | 67°F | 44°F | 87°F 2026 | 32°F 2021 | 30% |
| Mar 21 | 67°F | 44°F | 78°F 2026 | 31°F 2008 | 30% |
| Mar 22 | 68°F | 44°F | 87°F 2022 | 31°F 2008 | 29% |
| Mar 23 | 68°F | 44°F | 77°F 2026 | 29°F 2009 | 29% |
| Mar 24 | 68°F | 44°F | 80°F 2025 | 32°F 2009 | 29% |
| Mar 25 | 68°F | 45°F | 84°F 2025 | 32°F 2018 | 28% |
| Mar 26 | 68°F | 45°F | 80°F 2015 | 32°F 2020 | 28% |
| Mar 27 | 68°F | 45°F | 80°F 2009 | 30°F 2020 | 27% |
| Mar 28 | 69°F | 45°F | 78°F 2017 | 32°F 1999 | 27% |
| Mar 29 | 69°F | 45°F | 84°F 2026 | 30°F 2007 | 26% |
| Mar 30 | 69°F | 45°F | 82°F 2011 | 32°F 2005 | 26% |
| Mar 31 | 69°F | 45°F | 82°F 2021 | 28°F 2008 | 25% |
Chance of rain
- Chance of a wet day
Sunrise and sunset
Times for 2026, local time (PDT).
- March 1
- sunrise 6:41 AM, sunset 6:03 PM
- March 31
- sunrise 6:55 AM, sunset 7:32 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00047643 (Saint Helena), public domain. Records: NOAA GHCN-Daily, station USW00093227, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: 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.