Napa, CA Weather by Month
Napa, California has a mild Mediterranean climate with warm, dry summers and cool, wet winters. Average daily highs range from 56°F in January to 87°F in August, while nighttime lows drop to around 40°F in the winter and mid-50s in the summer
Napa, CA Weather by Month
You can click the image below to view the full-size weather chart for Napa, California.
January – Mild Winter Weather and Heavy Rainfall
Average high: 59°F (15°C)
Average low: 39°F (4°C)
Rainfall: 5.0 inches
Rainy days: 9
Daylight: 10 hours
January is one of the coolest and wettest months in Napa. Daytime temperatures typically reach around 59°F, while nighttime lows average about 39°F.
Rainfall averages about 5.0 inches across approximately 9 rainy days, making January one of the wettest months of the year. With around 10 hours of daylight, winter days are relatively short but still comfortable for exploring Napa’s indoor attractions and wineries.
Best for:
- Winery visits and wine tasting
- Cozy restaurants and cafes
- Scenic winter drives
- Indoor attractions
- Quiet Napa getaways
February – Cool Temperatures and Frequent Rain
Average high: 63°F (17°C)
Average low: 41°F (5°C)
Rainfall: 4.9 inches
Rainy days: 8
Daylight: 11 hours
February remains cool and wet in Napa, although temperatures begin to rise slightly compared with January. Afternoon highs average 63°F, while nighttime temperatures fall to around 41°F.
The month receives about 4.9 inches of rain over 8 rainy days. Increasing daylight, reaching approximately 11 hours, provides more time for sightseeing and exploring the Napa Valley.
Best for:
- Wine tasting
- Winery tours
- Scenic drives
- Restaurant experiences
- Relaxing weekend trips
March – Mild Spring Weather and Decreasing Rain
Average high: 66°F (19°C)
Average low: 43°F (6°C)
Rainfall: 3.9 inches
Rainy days: 8
Daylight: 12 hours
March brings noticeably milder spring weather to Napa. Highs average around 66°F, while lows remain cool at approximately 43°F.
Rainfall decreases to about 3.9 inches, although the month still averages 8 rainy days. With roughly 12 hours of daylight, March offers increasingly pleasant conditions for outdoor activities.
Best for:
- Vineyard sightseeing
- Scenic walks
- Wine tasting
- Exploring Napa Valley
- Early spring trips
April – Pleasant Spring Temperatures and Lighter Rain
Average high: 72°F (22°C)
Average low: 45°F (7°C)
Rainfall: 1.6 inches
Rainy days: 4
Daylight: 13 hours
April is a pleasant month in Napa, with warmer afternoons and considerably less rainfall. Average daytime highs reach 72°F, while nighttime lows stay around 45°F.
Rainfall drops to approximately 1.6 inches over 4 rainy days. Around 13 hours of daylight make April an excellent time to enjoy Napa’s vineyards, outdoor dining, and scenic countryside.
Best for:
- Vineyard tours
- Outdoor dining
- Hiking and walking
- Photography
- Exploring wineries
May – Warm, Dry Days and Long Daylight
Average high: 77°F (25°C)
Average low: 50°F (10°C)
Rainfall: 0.8 inches
Rainy days: 2
Daylight: 14 hours
May marks the beginning of Napa’s warm and increasingly dry summer season. Afternoon temperatures average around 77°F, while nighttime lows are a comfortable 50°F.
Rainfall falls to just 0.8 inches over about 2 rainy days. With approximately 14 hours of daylight, May offers plenty of time for outdoor activities, winery visits, and exploring the valley.
Best for:
- Wine tasting
- Vineyard tours
- Outdoor dining
- Hiking
- Scenic drives
June – Warm Weather and Almost No Rain
Average high: 82°F (28°C)
Average low: 54°F (12°C)
Rainfall: 0.2 inches
Rainy days: 0
Daylight: 15 hours
June brings warm, dry summer weather to Napa. Average highs reach about 82°F, while nighttime temperatures remain mild at around 54°F.
Rainfall is extremely limited at just 0.2 inches, with no rainy days in the averages. June also has the longest daylight of the year, at around 15 hours, making it ideal for spending long days outdoors.
Best for:
- Vineyard tours
- Outdoor wine tasting
- Hiking
- Cycling
- Long scenic drives
July – Hot, Dry Summer Weather
Average high: 82°F (28°C)
Average low: 55°F (13°C)
Rainfall: 0.01 inches
Rainy days: 0
Daylight: 14.5 hours
July is one of Napa’s warmest months and one of the driest. Daytime temperatures average around 82°F, while nighttime lows stay near 55°F.
Rainfall is almost nonexistent, averaging only about 0.01 inches, with no rainy days. Around 14.5 hours of daylight provide excellent conditions for enjoying Napa’s vineyards and outdoor attractions.
Best for:
- Wine tasting
- Vineyard visits
- Outdoor dining
- Cycling
- Poolside relaxation
August – Warm and Exceptionally Dry
Average high: 82°F (28°C)
Average low: 55°F (13°C)
Rainfall: 0.09 inches
Rainy days: 0
Daylight: 13.5 hours
August continues Napa’s warm, dry summer pattern. Average highs remain around 82°F, with nighttime lows of approximately 55°F.
Rainfall is extremely low at just 0.09 inches, and the averages show no rainy days. With about 13.5 hours of daylight, August remains an excellent month for outdoor activities and vineyard experiences.
Best for:
- Winery tours
- Wine tasting
- Outdoor dining
- Hiking in the morning
- Relaxing at resorts
September – Warmest Temperatures and Dry Conditions
Average high: 84°F (29°C)
Average low: 54°F (12°C)
Rainfall: 0.28 inches
Rainy days: 0
Daylight: 12.5 hours
September is the warmest month in Napa, with average daytime highs reaching about 84°F. Nights remain comfortable, with lows averaging around 54°F.
Rainfall remains very limited at approximately 0.28 inches, and there are no rainy days in the averages. Although daylight decreases to about 12.5 hours, September still offers long, warm days for exploring the valley.
Best for:
- Wine tasting
- Vineyard tours
- Harvest-season experiences
- Outdoor dining
- Scenic drives
October – Warm Fall Days and Increasing Rain
Average high: 77°F (25°C)
Average low: 50°F (10°C)
Rainfall: 1.4 inches
Rainy days: 2
Daylight: 11.5 hours
October brings a noticeable shift toward fall, with temperatures becoming more comfortable after the summer heat. Average highs reach around 77°F, while lows fall to about 50°F.
Rainfall increases to approximately 1.4 inches over 2 rainy days. With around 11.5 hours of daylight, October remains a great month for exploring Napa’s vineyards and enjoying the fall atmosphere.
Best for:
- Fall vineyard visits
- Wine tasting
- Harvest experiences
- Outdoor dining
- Photography
November – Cooler Days and Return of Winter Rain
Average high: 66°F (19°C)
Average low: 43°F (6°C)
Rainfall: 3.1 inches
Rainy days: 6
Daylight: 10 hours
November brings cooler temperatures and a significant increase in rainfall. Daytime highs average about 66°F, while nighttime lows drop to around 43°F.
Rainfall reaches approximately 3.1 inches across 6 rainy days. Daylight decreases to about 10 hours, making November feel noticeably more like winter while still offering mild daytime conditions.
Best for:
- Wine tasting
- Cozy restaurants
- Scenic drives
- Indoor winery experiences
- Relaxed weekend trips
December – Cool Winter Weather and Heavy Rain
Average high: 59°F (15°C)
Average low: 39°F (4°C)
Rainfall: 4.8 inches
Rainy days: 8
Daylight: 9.5 hours
December is one of Napa’s coolest and wettest months. Average daytime temperatures reach about 59°F, while nighttime lows fall to around 39°F.
The month receives approximately 4.8 inches of rainfall across 8 rainy days. December also has the shortest daylight of the year, at about 9.5 hours, but temperatures remain relatively mild compared with many other winter destinations.
Best for:
- Winery visits
- Wine tasting
- Cozy dining
- Holiday getaways
- Scenic winter trips
Napa, CA Weather by Month Table
| Month | Avg High °F (°C) | Avg Low °F (°C) | Rainfall (inches) | Rainy Days | Sun (hrs/day) |
|---|---|---|---|---|---|
| January | 59°F (15°C) | 39°F (4°C) | 5.0 | 9 | 10 |
| February | 63°F (17°C) | 41°F (5°C) | 4.9 | 8 | 11 |
| March | 66°F (19°C) | 43°F (6°C) | 3.9 | 8 | 12 |
| April | 72°F (22°C) | 45°F (7°C) | 1.6 | 4 | 13 |
| May | 77°F (25°C) | 50°F (10°C) | 0.8 | 2 | 14 |
| June | 82°F (28°C) | 54°F (12°C) | 0.2 | 0 | 15 |
| July | 82°F (28°C) | 55°F (13°C) | 0.01 | 0 | 14.5 |
| August | 82°F (28°C) | 55°F (13°C) | 0.09 | 0 | 13.5 |
| September | 84°F (29°C) | 54°F (12°C) | 0.28 | 0 | 12.5 |
| October | 77°F (25°C) | 50°F (10°C) | 1.4 | 2 | 11.5 |
| November | 66°F (19°C) | 43°F (6°C) | 3.1 | 6 | 10 |
| December | 59°F (15°C) | 39°F (4°C) | 4.8 | 8 | 9.5 |
20 FAQs About Napa Weather
- What is the weather like in Napa year-round?
Napa has a Mediterranean-style climate with mild, wetter winters and warm, very dry summers. Rainfall is concentrated mainly from late fall through early spring, while summer is typically sunny and nearly rain-free. - What is the best month to visit Napa for good weather?
May, June, September, and October are among the best months for comfortable temperatures, relatively dry conditions, and plenty of daylight. - What is the hottest month in Napa?
September is typically the warmest month in the data provided, with an average high of about 84°F (29°C). - What is the coldest month in Napa?
January and December are among the coolest months, with average highs around 59°F (15°C) and nighttime lows around 39°F (4°C). - Does it snow in Napa?
Snow is extremely rare in Napa. Winter temperatures are generally mild, and typical weather conditions are dominated by rain rather than snow. - What is Napa like in January?
January is cool and rainy, with an average high of 59°F, a low of 39°F, and about 5 inches of rainfall. It is a good month for wine tasting, restaurants, and indoor activities. - Does it rain a lot in Napa?
Rainfall varies dramatically by season. Winter can be quite wet, while June through September are exceptionally dry. The data provided shows rainfall of only 0.01–0.28 inches during July through September. - What is the rainiest month in Napa?
January is the wettest month in the provided data, receiving about 5.0 inches of rainfall across approximately 9 rainy days. - What is Napa weather like in spring?
Spring is mild and increasingly dry. Average highs rise from about 66°F in March to 77°F in May, while rainfall declines significantly. - What is Napa weather like in summer?
Summers are warm, sunny, and very dry. Average highs are around 82°F in June through August, with September reaching about 84°F. - Is Napa hot in July?
July is warm rather than consistently extreme, with an average high of approximately 82°F (28°C). However, occasional heat waves can push temperatures much higher; NWS climate records show Napa can reach the 100s during extreme events. - Is August a good time to visit Napa?
Yes. August is warm and exceptionally dry, with an average high of 82°F, around 0.09 inches of rainfall, and approximately 13.5 hours of daylight. - Is September a good month for Napa wine country?
Yes. September combines warm weather with very little rainfall. It is also an important time in Napa’s wine country because of the grape harvest season. - What is Napa like in October?
October brings comfortable fall temperatures, with an average high of 77°F (25°C) and a low of 50°F (10°C). Rainfall begins to increase, but the month remains relatively dry. - What is Napa weather like in November?
November is cooler and noticeably wetter. Average highs are around 66°F, lows around 43°F, and rainfall increases to approximately 3.1 inches. - What is Napa weather like in December?
December is cool and rainy, with average highs of 59°F (15°C) and lows of 39°F (4°C). It receives about 4.8 inches of rainfall and has around 9.5 hours of daylight. - What month has the most daylight in Napa?
June has the most daylight, at approximately 15 hours per day in the data provided. - What month has the least daylight in Napa?
December has the shortest days, with approximately 9.5 hours of daylight. - What should I wear in Napa?
Clothing depends on the season. Light layers work well in spring and fall, while breathable clothing is useful during summer. In winter, bring a waterproof jacket and warmer layers for cool evenings. - What is the best season for outdoor activities in Napa?
Spring and fall are especially comfortable for outdoor activities because temperatures are generally mild. Summer is also excellent for outdoor activities, although afternoons can become quite warm. The NWS climate data confirms that Napa’s summer conditions can vary considerably, including occasional periods of very high temperatures.
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