Napa weather in March

In March, Napa sees average daytime highs of 65°F and overnight lows near 46°F, with 3.4 in of rain across 8.4 wet days and about 11.7 hours of daylight. It is the 8th-warmest and 4th-wettest month of the year here.

Highs climb over the month, from about 63°F in the first days to 66°F by the end. The sky is clear or mostly clear about 36% of the time in March, and the air most often feels dry.

Daylight stretches from about 11 h 06 min at the start of March to 12 h 18 min by month's end. Set against the rest of the year, March is Napa's 9th-clearest and 6th-windiest month. For the whole year in context, see Napa's year-round climate.

Daytime high
65°
8th warmest
Overnight low
46°
4th coldest
Rainfall
3.4 in
8.4 wet days
Daylight
11 h 42 min
6:28 AM – 6:10 PM
Cloud cover
56%
9th clearest
Wind
5 mph
6th windiest
Solar energy
4.55 kWh/m²
Travel score
6.2
out of 10

Napa is city in Napa County, California, United States.

Density
1,721/km²
people per km²
Founded
1872

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in March

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 63°F in the first days to 66°F by the end.

A typical March day in Napa reaches about 65°F in the afternoon and slips back to 46°F overnight — a 19°F spread between the day's warmth and the night's chill. On most days the high lands between 56°F and 75°F. Set against its neighbours, March runs about 4°F warmer than February and about 5°F cooler than April.

30°40°50°60°70°80°151015202531
Avg high (°F)Avg low (°F)
16244
26244
36345
46345
56345
66445
76445
86445
96445
106446
116546
126546
136546
146546
156546
166546
176546
186546
196546
206546
216546
226546
236646
246647
256647
266647
276647
286647
296647
306647
316647

Napa weather by month

How March compares with the rest of the year at a glance. March is the 8th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysDaylight (hours)Travel score
Jan58° / 42°4.69.49.64.3
Feb61° / 44°4.68.610.55.1
Mar65° / 46°3.48.411.76.2
Apr69° / 48°1.54.9137.4
May76° / 52°0.83.2148.4
Jun82° / 56°0.20.914.68.1
Jul84° / 57°0.00.114.47.6
Aug84° / 57°0.00.213.57.5
Sep83° / 56°0.10.412.38.0
Oct76° / 52°1.02.9118.5
Nov65° / 46°2.25.99.96.5
Dec57° / 42°4.39.39.44.3

Cloud cover in March

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in March.

Beyond those clear spells, partly cloudy skies cover about 12% of March, with mostly cloudy or overcast conditions the remaining 51%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14852
24852
34951
44852
54852
64951
74951
84852
94852
104852
114852
124852
134753
144753
154753
164654
174654
184753
194654
204654
214753
224852
234951
244951
255050
265050
275149
285248
295248
305248
315446

Chance of precipitation in March

Any precipitation

Napa gets around 3.4 in of rain over 8.4 wet days in March. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 26% and peaks near 31% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%151015202531
Rain chance (%)
131
230
330
429
529
628
728
828
927
1027
1126
1226
1326
1426
1526
1627
1727
1827
1928
2027
2127
2226
2326
2425
2524
2624
2723
2823
2922
3021
3121

Humidity in March

DryComfortableHumidMuggyOppressiveMiserable

Most of March feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, March lands in the dry band about 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
1991
2991
3991
4991
5991
6991
7991
8991
9991
10991
11991
12991
13991
14991
15991
16991
17991
18991
19991
20991
21991
22991
23991
24991
25991
26991
27991
28991
29991
30991
31991

Wind in March

Winds average 5 mph in March.

Across March, daily wind ranges from about 5 mph on the calmest days to 5 mph at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (mph)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in March

DaylightNight

Daylight runs from about 11 h 06 min at the start of March to 12 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 72 minutes over March. Sunrise moves from 6:50 AM to 6:04 AM, and sunset from 5:54 PM to 6:24 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.16:505:54
211.16:495:55
311.16:485:56
411.26:465:58
511.26:455:59
611.36:436:00
711.36:426:01
811.46:406:02
911.46:396:03
1011.46:376:04
1111.56:366:05
1211.56:346:06
1311.66:336:07
1411.66:316:08
1511.76:306:09
1611.76:286:10
1711.76:266:11
1811.86:256:12
1911.86:236:12
2011.96:226:13
2111.96:206:14
2211.96:196:15
2312.06:176:16
2412.06:156:17
2512.16:146:18
2612.16:126:19
2712.26:116:20
2812.26:096:21
2912.26:076:22
3012.36:066:23
3112.36:046:24

Solar energy in March

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in March, about 4.55 kWh/m².

For context, solar energy here swings from a low near 2.08 kWh/m² to a high of 8.05 kWh/m² in July across the year — March's 4.55 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
13.8Moderate
23.9Moderate
33.9Moderate
44.0Moderate
54.0Bright
64.1Bright
74.1Bright
84.2Bright
94.2Bright
104.3Bright
114.3Bright
124.4Bright
134.4Bright
144.5Bright
154.5Bright
164.5Bright
174.6Bright
184.6Bright
194.7Bright
204.7Bright
214.8Bright
224.8Bright
234.9Bright
245.0Bright
255.0Bright
265.1Bright
275.1Bright
285.2Bright
295.2Bright
305.3Bright
315.3Bright
Planning a trip in March

Hazard calendar for Napa

In seasonPeak

In March, Napa sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Napa's rainy season runs November–March, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is March a good time to visit Napa?

Our two travel scores rate March for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.2
Sightseeing
9th-best month of the year
2.2
Beach & pool
9th-best month of the year

March is a reasonable time to visit Napa for sightseeing.

What to pack for Napa in March

From March's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In March, Napa sees daytime highs around 65°F and nights near 46°F. Worth packing: a warm layer, rain gear and sun protection. About 8 days see rain.

a warm layerrain gearsun protection

Sea temperature near Napa in March

The nearest coast averages about 54°F in March — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 35 mi away) is warmest in September at about 58°F and coldest in April near 53°F.

The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.

52°54°56°58°60°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°F)Comfort
Jan53Bracing
Feb53Bracing
Mar54Bracing
Apr53Bracing
May53Bracing
Jun54Bracing
Jul56Bracing
Aug58Bracing
Sep58Bracing
Oct57Bracing
Nov55Bracing
Dec54Bracing

UV index in Napa in March

LowModerateHighVery highExtreme

Clear-sky midday UV in March peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Napa peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 at about 2 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highExtremeVery highHighModerateJun 23UV 10Dec 13UV 2
UV index (midday)Level
Jan2Moderate
Feb4Moderate
Mar5Moderate
Apr6High
May9Very high
Jun10Extreme
Jul10Extreme
Aug9Very high
Sep6High
Oct5High
Nov2Moderate
Dec2Low

Air quality in Napa in March

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where March falls, not just the annual average.

Air quality in Napa is worst in September — around 29 µg/m³ PM2.5 (moderate), about 4.2× the cleanest month (June, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateSep 1829 µg/m³Jun 127 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb13Moderate
Mar13Moderate
Apr10Good
May8Good
Jun7Good
Jul10Good
Aug25Moderate
Sep29Moderate
Oct27Moderate
Nov16Moderate
Dec12Good
Location & terrain

Where is Napa?

Napa sits at 38.3°N, 122.3°W, 20 ft above sea level, in United States. The nearest listed city is American Canyon, 8.7 mi away.

Topography around Napa

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Napa.

Within 2 miles, the terrain around Napa has only modest variations in elevation — a maximum elevation change of 492 ft around an average of 79 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,585 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,895 ft.

The land around Napa is covered by artificial surfaces (45%) and trees (33%) within 2 miles, trees (38%) and grassland (38%) within 10 miles, and trees (29%) and grassland (29%) within 50 miles.

2 miles
492 ft
10 miles
2,585 ft
50 miles
4,895 ft
treesshrubsgrasslandcroplandartificial surfaceswaterwetland
March weather nearby: American Canyon 8.7 mi · Agua Caliente 11 mi · Vallejo 14 mi · Fairfield 14 mi · Suisun 14 mi · Vacaville 17 mi · Benicia 19 mi · Hercules 19 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Napa (38.2971°, -122.2855°, elevation 20 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).