Napa Weather
Town • San Francisco Bay Area
Downtown Napa grew up at the farthest point boats could reach on the Napa River, where Nathan Coombs laid out the town in 1847. Steamboats from San Francisco once landed here. Today the riverfront, First Street, and the Oxbow district form the walkable core of the county's largest city. Napa Creek joins the river in the middle of downtown. Napa sits farther south and closer to San Pablo Bay than any other Napa Valley town. That makes it the valley's front door for both cool bay air and winter floodwater.
Plan your week
10-Day Forecast
Hour by hour
Hourly Forecast
Current Conditions
Comfort Breakdown
Napa weather today and through the year
It's 53°F at Napa right now (feels like 51°F), with 2 mph wind and a comfort score of 77. Today's forecast high at Napa is 60°F, 6°F below the mid November normal of 66°F. No fog in the forecast for today at Napa. In November, 18% of morning hours here are foggy on average. The best window today is 10 AM to 1 PM, at about 52°F with a 3 mph wind (comfort 61).
August is the warmest month at Napa, with an average high of 87°F. December is the coldest, with an average low of 38°F. December is the wettest month (5.3 in.), out of about 26.1 in. a year. By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Napa are September, October, and July. The best hours are usually 10 AM to 1 PM in September, 11 AM to 2 PM in October, and 10 AM to 1 PM in July.
Napa sits at the south end of the valley, where it opens onto the tidal marshes of San Pablo Bay, and that opening sets its summer weather. On most summer afternoons a southerly breeze pulls bay air up the Napa River and across Carneros, fed by Pacific air that pours through the Petaluma Gap. Downtown gets that cooling first, so its afternoons usually top out a few degrees lower than towns farther up the valley, such as Yountville.
Forecast updated November 15, 2026 at 4:00 AM PST. Climate figures come from NOAA 1991-2020 normals. Hourly patterns come from NOAA's HRRR hourly analysis from September 2014 to April 2026.
What to expect at Napa in the next few days
No active National Weather Service alerts for this location.
Fog
No fog in the forecast for today at Napa. In November, 18% of morning hours here are foggy on average.
Best time to go
The best window today is 10 AM to 1 PM, at about 52°F with a 3 mph wind (comfort 61).
Best day this week
Of the next 7 days, Friday looks best for Napa, with a 59°F high and midday comfort near 75. Wednesday looks weakest (50).
Rain
Next good chance of rain: today (70%, about 0.43 in.).
Live weather map
Weather around Napa right now
Overcast and 53° at Napa right now.
About the live weather map for Napa
The map centers on Napa and stacks fog, satellite clouds, and precipitation radar on one view. Clouds come from the GOES-West satellite and rain from NOAA radar, and both show current conditions. Fog comes from our HRRR-based fog model, and the slider steps through its forecast for the next 12 hours.
Dots mark nearby places with their current temperature, colored by comfort score. Use the layer buttons to turn any layer off, or open the full map for every destination in the region.
Nearby Temperature Comparison
Conditions at nearby San Francisco Bay Area destinations
Tip: Bay Area temperatures can change by 20 to 30°F over a short distance because of microclimates.
Napa vs nearby places
Typical summer conditions compared with Napa, from the same NOAA HRRR hourly record. The list shows the closest places, then nearby places whose climate differs the most.
| Place | Distance | Summer afternoons | Morning fog | Afternoon wind | Compared with Napa |
|---|---|---|---|---|---|
| Wooden Valley | 7.6 mi | +2°F | 3% | 10 mph | less summer morning fog (3% vs 25% of morning hours) |
| Yountville | 8.2 mi | +4°F | 29% | 8 mph | about 4°F warmer on summer afternoons |
| American Canyon | 8.6 mi | -6°F | 20% | 11 mph | about 6°F cooler on summer afternoons |
| Winters | 23.2 mi | +9°F | 1% | 7 mph | less summer morning fog (1% vs 25% of morning hours) and about 9°F warmer on summer afternoons |
| San Pablo | 23.4 mi | -11°F | 29% | 10 mph | about 11°F cooler on summer afternoons |
| Wildcat Canyon Regional Park | 25 mi | -15°F | 42% | 11 mph | about 15°F cooler on summer afternoons and more summer morning fog (42% vs 25% of morning hours) |
Places with a climate like Napa's
- Morgan Hill (88 mi away): nearly the same temperatures every month
- Rutherford (13 mi away): nearly the same temperatures every month
- St. Helena (17 mi away): nearly the same temperatures every month
Climate Dashboard
Current conditions vs. NOAA normals and recent destination baseline
What the Napa climate comparisons mean
These cards compare recent conditions at Napa with the available local baseline. Temperature and year-to-date rainfall use long-term normals when available. Fog, sunshine, wind, and comfort use the matching recent or modeled baseline identified on each card.
Positive and negative differences describe how Napa departs from its own usual pattern. They should not be read as a direct comparison with another city or as a forecast beyond the period shown.
Napa weather by month
August is the warmest month at Napa, with an average high of 87°F. December is the coldest, with an average low of 38°F. December is the wettest month (5.3 in.), out of about 26.1 in. a year. Morning fog peaks in July, when fog or low cloud covers 30% of the hours from 6 to 10 AM. June has the clearest middays, with clouds covering about 10% of the sky from 11 AM to 3 PM.
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Napa are September, October, and July. The best hours are usually 10 AM to 1 PM in September, 11 AM to 2 PM in October, and 10 AM to 1 PM in July.
| Month | Avg high | Avg low | Rain | Rainy days | Morning fog | Midday cloud | Afternoon wind | Daylight | Comfort |
|---|---|---|---|---|---|---|---|---|---|
| Jan | 57°F | 38°F | 5.2 in | 10 | 24% | 32% | 5 mph | 9.8 h | 44 |
| Feb | 62°F | 41°F | 5.0 in | 9 | 14% | 24% | 6 mph | 10.7 h | 51 |
| Mar | 66°F | 43°F | 3.7 in | 8 | 15% | 29% | 7 mph | 11.9 h | 68 |
| Apr | 71°F | 45°F | 1.6 in | 5 | 14% | 22% | 8 mph | 13.2 h | 78 |
| May | 77°F | 49°F | 0.9 in | 4 | 15% | 19% | 9 mph | 14.3 h | 81 |
| Jun | 84°F | 53°F | 0.2 in | 2 | 17% | 10% | 10 mph | 14.8 h | 81 |
| Jul | 87°F | 55°F | 0.0 in | 0 | 30% | 11% | 9 mph | 14.6 h | 82 |
| Aug | 87°F | 55°F | 0.1 in | 1 | 27% | 11% | 8 mph | 13.6 h | 82 |
| Sep | 85°F | 53°F | 0.1 in | 1 | 21% | 13% | 8 mph | 12.3 h | 85 |
| Oct | 78°F | 48°F | 1.3 in | 5 | 19% | 15% | 6 mph | 11.1 h | 83 |
| Nov | 66°F | 42°F | 2.6 in | 7 | 18% | 21% | 5 mph | 10.0 h | 71 |
| Dec | 57°F | 38°F | 5.3 in | 10 | 26% | 34% | 5 mph | 9.5 h | 38 |
Morning fog is the share of hours from 6 to 10 AM with fog or low cloud. Midday cloud is the average from 11 AM to 3 PM, and afternoon wind is the average from 1 to 5 PM. The highlighted rows are the most comfortable months.
In summer, recent daily NOAA readings at Napa average about 7°F cooler than the 1991-2020 normals. The normals average over a wider area that also covers nearby terrain. Read the monthly highs as a rough range, and use the recent months below for what Napa has actually seen.
What makes Napa's weather different
When the fog burns off
10 AMwhen July fog usually thins (41% foggy at 8 AM)
Fog or low cloud covers Napa in 41% of 8 AM hours in July, the foggiest month. It usually thins to a third of that by 10 AM. February mornings are the least foggy (14%).
When the wind picks up
1 PMwhen afternoon wind builds, March–October
From March through October, wind at Napa typically builds after 1 PM. In June it peaks around 4 PM, averaging 11 mph with 3% of those hours windy, while mornings average 4 mph.
Hot hours
1 habove 85°F on a typical August afternoon
In August, the average temperature stays at or above 85°F for 1 hour a day.
Microclimate
−6°FAmerican Canyon, 8.6 mi away, on summer afternoons
American Canyon, 8.6 miles away, runs about 6°F cooler than Napa on summer afternoons.
Daylight
9.5–14.8 hof daylight, Dec to Jun
Days at Napa range from about 9.5 hours in December to 14.8 hours in June. In mid-June the sun sets around 8:33 PM, and in mid-December around 4:54 PM.
Seasons at Napa
- Warm seasonJun 25 – Sep 25 · highs 84°F+
The warm season lasts about 3.1 months, from Jun 25 to Sep 25, when the average high is 84°F or warmer. Highs peak around Aug 8 at about 87°F.
- Hot afternoonsJun 30 – Sep 23 · highs 85°F+
Average highs reach 85°F or more from Jun 30 to Sep 23.
- Cool seasonNov 27 – Feb 27 · highs 64°F or lower
The cool season runs from Nov 27 to Feb 27, when the average high is 64°F or lower. The coldest nights come around Dec 8, with an average low near 38°F.
- Rainy seasonNov 5 – Apr 8 · 84% of the year's rain
The rainy season runs from Nov 5 to Apr 8, when a day has at least a 20% chance of measurable rain. That stretch brings 84% of the year's rain.
The dark line marks today. Season dates come from the smoothed daily NOAA 1991-2020 normals. Counting from Oct. 1, a typical year has its first inch of rain by Oct 25 and half of its annual total by Jan 23.
Days per year and extremes (Nov 1, 2024 to Oct 31, 2026)
This record runs from Nov 1, 2024 to Oct 31, 2026. Over this record, Napa averaged 17 days a year at 90°F or hotter and 3 nights a year at or below freezing. It averaged 17 days a year with at least half an inch of rain and 0 afternoons with wind of 20 mph or more at 2 PM. About 135 mornings a year had 3 or more hours of fog or low cloud.
In the same record, the hottest day was Sep 9, 2026 (101°F) and the coldest night was Feb 10, 2025 (30°F). The wettest day was Nov 21, 2024 (2.29 in.), and the strongest 2 PM gust was 37 mph on Feb 4, 2025.
- 17days at 90°F or hotter
- 3nights at or below freezing
- 17days with ½ in. of rain or more
- 0afternoons with 20+ mph wind
- 135mornings with 3+ hours of fog or low cloud
- Hottest day101°FSep 9, 2026
- Coldest night30°FFeb 10, 2025
- Wettest day2.29 inNov 21, 2024
- Strongest 2 PM gust37 mphFeb 4, 2025
What shapes Napa's weather
The bay breeze that cools Napa also carries the marine layer, the sheet of low cloud that forms over the cold ocean and bay. On many summer mornings that low cloud slides up from the bay and covers Napa. It then burns back toward the water by late morning, while towns farther up the valley see fog less often. When the sea breeze weakens in September and October, Napa heats up almost as much as the rest of the valley. Dry northeast wind blowing off the Vaca Mountains has the same effect.
Winter storms matter more downtown than almost anywhere else in the valley. The Napa River drains the whole valley, and Napa Creek drains the hills to the west. The two meet downtown close to sea level, where the river still rises and falls with the tide. The city describes river floods here as slow-rise events, while Napa Creek can flood quickly on its own.
Tips for visiting Napa
Watch river stages during big storms
The city says minor flooding begins when the Napa River reaches 26 feet at the Oak Knoll gauge. When that happens, it closes streets near the river, including parts of First, Second, Third, and Soscol.
Expect Napa Creek to rise faster
River floods here usually build slowly and predictably, but the city warns that Napa Creek can flood independently of the river.
Take the VINE bus upvalley
VINE's main valley bus runs every day of the week from the Soscol Gateway Transit Center to Yountville, St. Helena, and Calistoga.
Walk the river on the Bay Trail
The Napa River & Bay Trail is a paved path open sunrise to sunset, with Kennedy Park as a city trailhead. Leashed dogs are allowed.
Bike to Yountville on the Vine Trail
A finished Vine Trail section runs from Kennedy Park through downtown and Oak Knoll to Yountville, separate from car traffic.
Napa through the seasons
- Spring (March–May)
- Spring brings green hills, mild afternoons, and the last storms of the season. The bay breeze returns by May, so late-day walks along the river turn breezy.
- Summer (June–August)
- Mornings often start under low cloud from San Pablo Bay, and afternoons turn warm to hot. NOAA's long-running weather stations put summer highs at Napa several degrees below St. Helena's.
- Fall (September–October)
- Some of the year's hottest days come in September, when the sea breeze fades. Dry northeast wind events raise fire danger in the hills around the city.
- Winter (November–February)
- Winter is the rainy season. Heavy storms can push the Napa River toward flood stage, and the city closes low streets near the river when that happens.
Activities and the weather that matters
- Riverfront walking and dining: Riverfront tables are best on mild afternoons. In summer the bay breeze cools them quickly after sunset, along the same river where steamboats once carried passengers to San Francisco.
- Cycling the Vine Trail: Calm mornings are easiest. Summer afternoons bring a steady south wind up the valley, a tailwind to Yountville and a headwind on the way back.
- Wine tasting downtown: Indoor tasting rooms within walking distance make downtown the valley's best rainy-day fallback in winter.
Official sources and current conditions
- City of Napa: flood inundation areas
- VINE Transit Route 10 (Up Valley Connector)
- Napa Open Space District: Napa River & Bay Trail
- Napa Valley Vine Trail
- National Weather Service, San Francisco Bay Area
Numbers on this page come from NOAA data. The text draws on the official sources linked above.
Historical Climate Data
Long-term weather patterns and climate data
Data sources: Recent temperatures come from NOAA URMA and recent precipitation from NOAA Stage IV. Fog, cloud, wind, humidity, and sunshine come from NOAA HRRR, and long-term baselines from NOAA 1991-2020 climate normals.
Climate Overview
Based on NOAA 30-year temperature/rain normals (1991-2020) with recent fog/sun baseline
🌟 Best Months to Visit
⚠️ Challenging Months
Monthly Breakdown
| Month | Comfort | High/Low | ☀️ Sun | 🌫️ Fog | 💧 Rain | Perfect |
|---|---|---|---|---|---|---|
| November 2024 | 79 | 62.9° / 43° | 6.2h | 6d | 7.47" | 20 |
| December 2024 | 71 | 59.5° / 43.3° | 4.8h | 11d | 5.89" | 13 |
| January 2025 | 82 | 59.9° / 39.1° | 7h | 7d | 0.25" | 19 |
| February 2025 | 75 | 61.4° / 42.2° | 6.3h | 3d | 8.16" | 15 |
| March 2025 | 81 | 62.5° / 43.7° | 7.6h | 5d | 2.14" | 19 |
| April 2025 | 90 | 68.3° / 47.1° | 9.5h | 9d | 0.33" | 27 |
| May 2025 | 94 | 76.1° / 51° | 11.8h | 4d | 0.12" | 31 |
| June 2025 | 93 | 76.3° / 52.6° | 11.8h | 9d | 0" | 30 |
| July 2025 | 92 | 75.9° / 55.4° | 11.3h | 11d | 0" | 31 |
| August 2025 | 91 | 82.6° / 56.4° | 10.9h | 5d | 0" | 30 |
| September 2025 | 90 | 80.2° / 58.6° | 9.4h | 5d | 0.3" | 28 |
| October 2025 | 85 | 73.1° / 51.6° | 7.3h | 8d | 1.28" | 23 |
| November 2025 | 79 | 64° / 48.1° | 6.4h | 11d | 3.69" | 16 |
| December 2025 | 65 | 55.5° / 43.1° | 4.5h | 17d | 4.44" | 5 |
| January 2026 | 78 | 60.9° / 41.2° | 6.4h | 3d | 3.59" | 21 |
| February 2026 | 78 | 63.8° / 44.9° | 6.2h | 6d | 3.7" | 15 |
| March 2026 | 94 | 77.1° / 48.5° | 9.7h | 4d | 0.01" | 30 |
| April 2026 | 86 | 68.9° / 47.9° | 9.1h | 5d | 3.34" | 22 |
| May 2026 | 91 | 74° / 52.3° | 11.4h | 5d | 0.91" | 30 |
| June 2026 | 93 | 79.1° / 55.3° | 12.2h | 5d | 0" | 29 |
| July 2026 | 93 | 80.2° / 56.4° | 11.2h | 5d | 0" | 31 |
| August 2026 | 90 | 79.1° / 56.3° | 10.1h | 13d | 0" | 30 |
| September 2026 | 91 | 79.2° / 54.6° | 9.6h | 9d | 0.2" | 27 |
| October 2026 | 90 | 78.5° / 48.6° | 8.2h | 2d | 0.3" | 28 |
Climate Trends
Average Temperature by Month
About the Napa climate charts
The temperature chart compares average monthly highs and lows at Napa, showing both the seasonal cycle and the typical day-to-night range. The comfort chart summarizes how often the combined weather pattern is favorable rather than judging temperature alone.
Precipitation shows the total recorded or modeled rainfall for each month at Napa. Sunshine compares average bright-sky hours with the daylight available, while fog shows the average number of morning fog or low-cloud hours per day. Switch between the chart tabs to compare the same months across each measure.
Hourly Temperature, Fog, Wind, Cloud Cover, and Solar Radiation Patterns
Average local hour by month from 2014-09-30 to 2026-04-30
- Temperature: At Napa, the warmest typical hour is 4 PM in August (85°F). The coldest is 7 AM in January (44°F).
- Fog: Fog or low cloud covers Napa in 41% of 8 AM hours in July, the foggiest month. It usually thins to a third of that by 10 AM. February mornings are the least foggy (14%).
- Wind: From March through October, wind at Napa typically builds after 1 PM. In June it peaks around 4 PM, averaging 11 mph with 3% of those hours windy, while mornings average 4 mph.
- Cloud Cover: June middays are the clearest at Napa (10% average cloud cover), and December middays are the cloudiest (34%).
- Solar Radiation: The strongest typical sun at Napa comes at 1 PM in June, averaging 984 W/m².
How to read the hourly heatmaps for Napa
This heatmap shows how average temperature at Napa changes by hour and month. Read left to right for the seasons and top to bottom for the time of day. Warmer colors mark the usual afternoon peaks, and cooler colors show overnight and winter lows.
This heatmap shows when fog or low cloud is most likely at Napa. Darker cells mark the months and hours when fog has been most common. They help separate overnight or morning fog from cloud that tends to linger into the afternoon.
This heatmap shows the typical hourly wind pattern at Napa through the year. It makes recurring afternoon wind, calmer overnight periods, and seasonal changes easier to compare than a single daily wind value.
This heatmap shows average cloud cover at Napa for every month and hour. Use it to see whether cloudiness is mainly an overnight and morning pattern or commonly persists during the part of the day you plan to visit.
This heatmap shows the average solar radiation reaching Napa by month and hour. Brighter cells indicate the strongest typical sun, while muted cells can reflect nighttime, shorter winter days, cloud cover, smoke, or terrain shading.
Each cell combines one month with one local hour. Hover over or focus on a cell for its value and sample coverage. The red marker shows the current month and hour.
How recent months compared at Napa
- October 2026 recap: October 2026 at Napa averaged a high of 78°F, 5°F warmer than October 2025 (73°F).
- Rain year: The 2025-26 rain year (Oct. 1 to Sep. 30) brought 21.2 in. of rain to Napa, 81% of the 26.1 in. normal.
Location Details
Napa weather questions
Everything you need to know about weather and visiting Napa
What is the weather like at Napa today?
It's 53°F at Napa right now, with a comfort score of 77 (great). Today's forecast high at Napa is 60°F, 6°F below the mid November normal of 66°F. The best window today is 10 AM to 1 PM, at about 52°F with a 3 mph wind (comfort 61).
What is the best month to visit Napa?
By typical temperature, wind, cloud, humidity, and rain odds, the most comfortable months at Napa are September, October, and July. The best hours are usually 10 AM to 1 PM in September, 11 AM to 2 PM in October, and 10 AM to 1 PM in July. The warm season lasts about 3.1 months, from Jun 25 to Sep 25, when the average high is 84°F or warmer. Highs peak around Aug 8 at about 87°F.
What are the warmest and coldest months at Napa?
August is the warmest month at Napa, with an average high of 87°F. December is the coldest, with an average low of 38°F.
When does the fog burn off at Napa?
Fog or low cloud covers Napa in 41% of 8 AM hours in July, the foggiest month. It usually thins to a third of that by 10 AM. February mornings are the least foggy (14%).
When is it windiest at Napa?
From March through October, wind at Napa typically builds after 1 PM. In June it peaks around 4 PM, averaging 11 mph with 3% of those hours windy, while mornings average 4 mph.
How much rain does Napa get?
December is the wettest month (5.3 in.), out of about 26.1 in. a year. The rainy season runs from Nov 5 to Apr 8, when a day has at least a 20% chance of measurable rain. That stretch brings 84% of the year's rain. The 2025-26 rain year (Oct. 1 to Sep. 30) brought 21.2 in. of rain to Napa, 81% of the 26.1 in. normal.
How does Napa weather compare with American Canyon?
American Canyon, 8.6 miles away, runs about 6°F cooler than Napa on summer afternoons.
What kind of place is Napa?
Downtown Napa grew up at the farthest point boats could reach on the Napa River, where Nathan Coombs laid out the town in 1847. Steamboats from San Francisco once landed here. Today the riverfront, First Street, and the Oxbow district form the walkable core of the county's largest city. Napa Creek joins the river in the middle of downtown. Napa sits farther south and closer to San Pablo Bay than any other Napa Valley town. That makes it the valley's front door for both cool bay air and winter floodwater.
What is Napa weather like in November?
November at Napa averages a high of 66°F and a low of 42°F, with 2.6 in. of rain over about 7 rainy days. About 18% of morning hours are foggy. Afternoon wind averages 5 mph.
More about Napa weather
Guides that explain the weather here and nearby
- Napa Valley Weather Guide: Best Times to Visit and What to Expect
- Napa Weather in March: Late Rains, Wildflowers, and Shoulder Season Perks
- Wine Country Weather: Napa and Sonoma Explained
- Napa & Sonoma Day Trip: Best Weather Months to Visit Wine Country
- Napa Weather in October: Peak Harvest Season and What It Means for Visitors
- Napa Valley Weather by Month: When to Visit Wine Country
Data sources and methods
- Monthly temperatures and precipitation: NOAA 1991-2020 normals.
- Fog, cloud, wind, sun, and comfort by hour and month: NOAA's HRRR hourly analysis from September 2014 to April 2026.
- Daily records and recent months: NOAA URMA and HRRR analyses, plus NOAA Stage IV precipitation.
- Nearby comparisons and regional rankings use the same hourly HRRR summaries for every destination in the region.
- Alerts: National Weather Service. Tides and ocean temperature: NOAA CO-OPS, where shown.
- All statements on this page are computed from these datasets, apart from the “What shapes the weather” guide, which cites its sources inline.
- City of Napa, History of Napa (accessed 2026-10-27)
- City of Napa, Map of Flood Inundation Areas (accessed 2026-10-27)
- City of Napa, Phase 2 flood response area and street closures (accessed 2026-10-27)
- VINE Transit, Route 10 Up Valley Connector (accessed 2026-10-27)
- Napa County Regional Park and Open Space District, Napa River & Bay Trail (accessed 2026-10-27)
- Napa Valley Vine Trail Coalition, The Vine Trail (accessed 2026-10-27)
- NOAA NCEI 1991–2020 climate normals: Napa State Hospital, St. Helena, Angwin, and Markley Cove stations (accessed 2026-10-27)
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