January is the coldest and wettest month in Napa Valley. Temperature averages are at 37°F (3°C) for the low temperature and 55°F (13°C) for the high temperature. Expected rainfall is at 4 inches (111 mm).
Napa Valley Weather in February: As the final month of winter, February has the third coldest temperature in the year. The average low temperature increases a few degrees to 39°F (4°C) while the average high temperature sees a significant increase to 60°F (15°C).
In March, the temperature continues in an upward trend with the average high temperature rising to 64°F (18°C). The average low temperature sees a very small increase to just 40°F (5°C). Precipitation rates decrease to 3 inches (64 mm).
April sees beautiful spring weather in Napa. The average low and average high temperatures measure in at 42°F (5°C) and 68°F (20°C) respectively.
Napa Valley Weather in May: As the last month of spring, May brings warmer temperatures to Napa Valley. Despite the increase in temperature, the low temperature average and high temperature averages stay mild at 46°F (8°C) and 73°F (23°C). Average rainfall decreases to 1 inch (21 mm).
In June, the average high temperature sees a rather rapid increase to 78°F (26°C). The average low temperature increases to 50°F (10°C).
July is the hottest month of the year with the high temperature average peaking at 78°F (26°C). The low temperature average hits 53°F (11°C). July is also the driest month of the year with absolutely no rainfall to be expected.
Napa Valley Weather in August: Harvest season descends upon Napa Valley in August marking the start of the peak tourist season. During this month, the average low and average high temperature measure in at 52°F (11°C) and 80°F (26°C) respectively.
In September, the average high temperature remains the same at 80°F (27°C). On the other hand, the average low temperature sees a decrease to 49°F (10°C).
October brings cooler weather to Napa Valley and some light rain showers. The precipitation rate hits 1 inch (25 mm) while the average low and average high temperatures range between 43°F (6°C) and 74°F (23°C).
Napa Valley Weather in November: The downward trend in temperature continues in November as the average high temperatures sees a steep and rapid decline to 4°F (18°C). The average low temperature also sees a significant decrease to 39°F (4°C).
In December, the second coldest month of the year, the average high temperature falls to 56°F (13°C). Similarly, the average low temperature sinks to a frigid 36°F (2°C).
Napa Valley is a beautiful holiday destination especially when it comes to wine lovers and sommeliers. The harvest season is, without a doubt, one of the best times to visit Napa Valley. This season takes place between August through October and allows great tours of vineyards and wineries alike. To enjoy the best of Napa Valley’s autumn foliage, the best time to visit is in October as the leaves strike a beautiful balance of colors. For those who simply want to visit Napa Valley when the tourist crowds have thinned, it’s best to come in between March and May when the peak season dies down. For more affordable trips to Napa Valley, plan your trip between the chilly months of December, January and February.