Coastal Flood Advisory
Ends in 5 days 2 h
When
From 8 AM Saturday to 3 PM PDT Thursday.
Where
Bay Shoreline locations of San Francisco Bay, Monterey Bay and Big Sur Coast.
Issued for this forecast zone · National Weather Service San Francisco CA
What, impacts and precautionsHide details
What
Up to 1.9ft of inundation above ground level is possible in low-lying areas near shorelines and tidal waterways.
Impacts
High tides will result in flooding of low-lying infrastructure, isolated road closures, and coastal erosion. Rising tides will bring water and waves farther up the beach than normal, restricting escape from beaches and coastal areas.
Additional details
At the San Francisco tidal gauge, high tide is expected to be 1.1 ft above normal (6.9 ft MLLW) at 10:39 AM Saturday 10/24, 1.5 ft above normal (7.3 ft MLLW) at 11:07 AM Sunday 10/25, 1.6 ft above normal (7.4 ft MLLW) at 11:39 AM Monday 10/26, 1.8 ft above normal (7.6 ft MLLW) at 12:15 PM Tuesday 10/27, 1.9 ft above normal (7.7 ft MLLW) at 12:56 PM Wednesday 10/28, and 1.7 ft above normal (7.5 ft MLLW) at 01:43 PM Thursday 10/29. These predictions include up to 1.0 ft of surge that will enhance the astronomical tide and flooding threat. High tide varies up to 90 minutes earlier or later along the Pacific Coast and through the San Francisco Bay, respectively.
Precautionary actions
If travel is required, allow extra time as some roads may be closed. Do not drive around barricades or through water of unknown depth. Take the necessary actions to protect flood-prone property.
Areas: San Francisco; North Bay Interior Valleys; San Francisco Bay Shoreline; Northern Monterey Bay; Southern Monterey Bay and Big Sur Coast
See it on weather.gov (opens in a new tab)

Observed 12:05 PM PDT at KSTS

St. Helena, CA weather

Sunny and 72°22°.

Forecasts differ

Now 72°22°

Sunny

Wind: 6 mph9 km/h; From the west-northwest. Up to 6 mph9 km/h through 12 AM
Dew point: 43°6°; Comfortable
UV index: 4Moderate; Moderate until 4 PM
Air quality: 32Good; Main pollutant: PM2.5 (fine particles)
Pressure: 30.04 inHg1017 hPa; Falling slowly · −0.03 inHg−0.9 hPa in 3 h

No precipitation expected in the next 2 hours.

From forecast models

Next 48 hours

Good hours for

High 75°24° today at 4 PM
Below 60°16° tonight after 8 PM
Low 44°7° tomorrow at 7 AM
Above 60°16° tomorrow by 11 AM
Fog tomorrow night 3–8 AM

This afternoonUp to 75°24° by 4 PM · Clear
TonightDown to 46°8° by 4 AM · Clear
Tomorrow morningUp to 62°17° by 11 AM · Mostly cloudy
Tomorrow afternoonUp to 72°22° by 3 PM · Cloudy
Tomorrow nightDown to 43°6° by 5 AM · Partly cloudy
Monday morningUp to 58°14° by 11 AM · Partly cloudy

Hourly forecast, next 48 hours, in the place's local time
Hour	Conditions	Temperature	Feels like	Precipitation	Wind	Humidity	Cloud cover	UV index
Sat 12p	Sunny	68°20° (likely 68°20° to 75°24°)	68°20°	0%	3 mph5 km/h from NNE, gusts 11 mph17 km/h	41%	0%	4
Sat 1p	Sunny	72°22° (likely 71°22° to 77°25°)	72°22°	0%	2 mph3 km/h from N, gusts 8 mph12 km/h	37%	3%	4
Sat 2p	Sunny	74°23° (likely 72°22° to 78°26°)	74°23°	0%	1 mph2 km/h from WNW, gusts 7 mph11 km/h	35%	0%	4
Sat 3p	Sunny	74°23° (likely 72°22° to 79°26°)	74°23°	0%	1 mph2 km/h from W, gusts 7 mph11 km/h	34%	0%	3
Sat 4p	Sunny	75°24° (likely 71°22° to 79°26°)	75°24°	0%	0 mph0 km/h, gusts 6 mph10 km/h	34%	0%	2
Sat 5p	Sunny	74°23° (likely 69°21° to 74°23°)	75°24°	0%	0 mph0 km/h, gusts 11 mph18 km/h	35%	0%	2
Sat 6p	Clear	70°21° (likely 64°18° to 70°21°)	70°21°	0%	0 mph0 km/h, gusts 12 mph20 km/h	43%	0%	1
Sat 7p	Clear	66°19° (likely 59°15° to 66°19°)	66°19°	0%	0 mph0 km/h, gusts 9 mph14 km/h	52%	0%	0
Sat 8p	Clear	59°15° (likely 58°14° to 62°17°)	59°15°	0%	0 mph0 km/h, gusts 5 mph8 km/h	61%	0%	0
Sat 9p	Clear	56°13° (likely 56°13° to 59°15°)	56°13°	0%	0 mph0 km/h, gusts 3 mph5 km/h	64%	0%	0
Sat 10p	Clear	54°12° (likely 54°12° to 57°14°)	54°12°	0%	0 mph0 km/h, gusts 4 mph6 km/h	65%	0%	0
Sat 11p	Clear	52°11° (likely 52°11° to 56°13°)	52°11°	0%	0 mph0 km/h, gusts 3 mph5 km/h	68%	0%	0
Sun 12a	Clear	51°11° (likely 51°11° to 55°13°)	51°11°	0%	0 mph0 km/h, gusts 2 mph3 km/h	71%	5%	0
Sun 1a	Clear	50°10° (likely 50°10° to 54°12°)	50°10°	0%	0 mph0 km/h, gusts 2 mph4 km/h	72%	37%	0
Sun 2a	Clear	49°9° (likely 49°9° to 54°12°)	49°9°	0%	0 mph0 km/h, gusts 2 mph4 km/h	73%	41%	0
Sun 3a	Partly cloudy	47°8° (likely 47°8° to 54°12°)	47°8°	0%	0 mph0 km/h, gusts 2 mph4 km/h	75%	53%	0
Sun 4a	Cloudy	46°8° (likely 46°8° to 53°12°)	46°8°	0%	0 mph0 km/h, gusts 3 mph4 km/h	77%	65%	0
Sun 5a	Cloudy	46°8° (likely 46°8° to 52°11°)	46°8°	0%	0 mph0 km/h, gusts 2 mph4 km/h	76%	68%	0
Sun 6a	Cloudy	45°7° (likely 45°7° to 50°10°)	45°7°	0%	0 mph0 km/h, gusts 3 mph5 km/h	77%	68%	0
Sun 7a	Partly sunny	44°7° (likely 44°7° to 50°10°)	44°7°	0%	0 mph0 km/h, gusts 3 mph5 km/h	82%	58%	0
Sun 8a	Partly sunny	44°7° (likely 44°7° to 51°11°)	45°7°	0%	1 mph2 km/h from NNE, gusts 3 mph5 km/h	82%	68%	0
Sun 9a	Cloudy	50°10° (likely 50°10° to 56°13°)	50°10°	0%	2 mph3 km/h from ENE, gusts 4 mph6 km/h	75%	75%	1
Sun 10a	Cloudy	57°14° (likely 57°14° to 63°17°)	57°14°	0%	1 mph2 km/h from ESE, gusts 4 mph6 km/h	65%	78%	2
Sun 11a	Cloudy	62°17° (likely 62°17° to 68°20°)	62°17°	0%	1 mph2 km/h from SE, gusts 5 mph8 km/h	58%	80%	3
Sun 12p	Cloudy	67°19° (likely 66°19° to 71°22°)	67°19°	0%	1 mph2 km/h from SE, gusts 6 mph10 km/h	52%	82%	4
Sun 1p	Cloudy	69°21° (likely 69°21° to 73°23°)	69°21°	0%	1 mph2 km/h from SE, gusts 8 mph12 km/h	48%	83%	4
Sun 2p	Cloudy	71°22° (likely 69°21° to 74°23°)	71°22°	0%	1 mph2 km/h from SSE, gusts 8 mph13 km/h	46%	86%	4
Sun 3p	Cloudy	72°22° (likely 69°21° to 75°24°)	73°23°	0%	2 mph3 km/h from S, gusts 8 mph12 km/h	46%	87%	3
Sun 4p	Cloudy	71°22° (likely 68°20° to 73°23°)	71°22°	0%	2 mph3 km/h from SSW, gusts 10 mph15 km/h	46%	86%	2
Sun 5p	Cloudy	71°22° (likely 66°19° to 71°22°)	71°22°	0%	2 mph3 km/h from WSW, gusts 10 mph16 km/h	46%	88%	1
Sun 6p	Cloudy	67°19° (likely 62°17° to 67°19°)	67°19°	0%	1 mph2 km/h from WSW, gusts 8 mph13 km/h	55%	89%	0
Sun 7p	Cloudy	61°16° (likely 58°14° to 62°17°)	61°16°	0%	0 mph0 km/h, gusts 6 mph9 km/h	63%	92%	0
Sun 8p	Cloudy	58°14° (likely 56°13° to 59°15°)	58°14°	0%	0 mph0 km/h, gusts 9 mph15 km/h	71%	87%	0
Sun 9p	Mostly cloudy	55°13° (likely 55°13° to 56°13°)	55°13°	0%	0 mph0 km/h, gusts 9 mph14 km/h	77%	35%	0
Sun 10p	Clear	53°12° (likely 53°12° to 54°12°)	53°12°	0%	0 mph0 km/h, gusts 7 mph12 km/h	81%	6%	0
Sun 11p	Clear	51°11° (likely 51°11° to 52°11°)	51°11°	0%	0 mph0 km/h, gusts 6 mph9 km/h	85%	0%	0
Mon 12a	Clear	49°9° (likely 49°9° to 51°11°)	49°9°	0%	0 mph0 km/h, gusts 4 mph7 km/h	90%	0%	0
Mon 1a	Clear	47°8° (likely 47°8° to 50°10°)	47°8°	0%	0 mph0 km/h, gusts 5 mph9 km/h	95%	9%	0
Mon 2a	Clear	45°7° (likely 45°7° to 50°10°)	45°7°	0%	0 mph0 km/h, gusts 8 mph12 km/h	97%	20%	0
Mon 3a	Fog	44°7° (likely 44°7° to 50°10°)	44°7°	0%	0 mph0 km/h, gusts 5 mph9 km/h	100%	24%	0
Mon 4a	Fog	44°7° (likely 44°7° to 50°10°)	44°7°	0%	0 mph0 km/h, gusts 6 mph9 km/h	100%	40%	0
Mon 5a	Fog	43°6° (likely 43°6° to 51°11°)	43°6°	0%	1 mph2 km/h from W, gusts 7 mph11 km/h	100%	42%	0
Mon 6a	Fog	43°6° (likely 43°6° to 52°11°)	43°6°	0%	1 mph2 km/h from W, gusts 7 mph11 km/h	100%	54%	0
Mon 7a	Fog	43°6° (likely 43°6° to 51°11°)	43°6°	0%	1 mph2 km/h from W, gusts 8 mph13 km/h	100%	51%	0
Mon 8a	Partly sunny	44°7° (likely 44°7° to 51°11°)	44°7°	0%	2 mph3 km/h from W, gusts 8 mph14 km/h	100%	49%	0
Mon 9a	Partly sunny	48°9° (likely 48°9° to 55°13°)	48°9°	0%	2 mph3 km/h from W, gusts 10 mph16 km/h	97%	23%	1
Mon 10a	Partly sunny	53°12° (likely 53°12° to 60°16°)	53°12°	0%	2 mph3 km/h from W, gusts 15 mph24 km/h	93%	30%	2
Mon 11a	Mostly sunny	58°14° (likely 58°14° to 63°17°)	59°15°	0%	5 mph8 km/h from W, gusts 17 mph27 km/h	87%	14%	3

Days ahead

Shaded: typical range for these dates (1991–2020)

Today, Oct 24. Sunny. High 76°24°, low 44°7°. Typical 75°24° / 46°8°. Dry. Forecasts differ.
1. Afternoon
  noon–6 PM
  Sunny, 75°24°
  Dry
2. Evening
  6 PM–midnight
  Clear, 59°15°
  Dry
3. Overnight
  midnight–6 AM
  Partly cloudy, 46°8°
  Dry
Official NWS forecast
Today: Sunny. High near 76, with temperatures falling to around 74 in the afternoon. Northwest wind 0 to 3 mph.
Tonight: Mostly clear. Low around 44, with temperatures rising to around 46 overnight. Wind around 0 mph.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
72°22°–79°26°
Low, likely
44°7°–55°13°
Typical high / low
75°24° / 46°8°
Wind
11 mph17 km/h, gusts 22 mph35 km/h
UV peak
5
Tomorrow, Oct 25. Cloudy. High 74°23°, low 42°6°. Typical 74°23° / 46°8°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 44°7°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 72°22°
  Dry
3. Evening
  6 PM–midnight
  Mostly cloudy, 58°14°
  Dry
4. Overnight
  midnight–6 AM
  Fog, 43°6°
  Dry
Official NWS forecast
Day: Partly sunny. High near 74, with temperatures falling to around 71 in the afternoon. Southeast wind around 2 mph.
Night: Areas of fog after 1am. Mostly cloudy, with a low around 42. West northwest wind around 1 mph.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
69°21°–75°24°
Low, likely
42°6°–50°10°
Typical high / low
74°23° / 46°8°
Wind
8 mph13 km/h, gusts 15 mph24 km/h
UV peak
4
Monday, Oct 26. Fog. High 69°21°, low 40°4°. Typical 74°23° / 46°8°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Partly sunny, 44°7°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 68°20°
  Dry
3. Evening
  6 PM–midnight
  Clear, 55°13°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 47°8°
  Dry
Official NWS forecast
Day: Areas of fog before 8am. Mostly sunny, with a high near 69. West wind 1 to 6 mph.
Night: Patchy fog after 1am. Mostly clear, with a low around 40.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
65°18°–69°21°
Low, likely
40°4°–49°9°
Typical high / low
74°23° / 46°8°
Wind
9 mph14 km/h, gusts 24 mph39 km/h
UV peak
5
Tuesday, Oct 27. Fog. High 70°21°, low 42°6°. Typical 74°23° / 45°7°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 46°8°
  Dry
2. Afternoon
  noon–6 PM
  Mostly sunny, 68°20°
  Dry
3. Evening
  6 PM–midnight
  Clear, 56°13°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 48°9°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Patchy fog before 9am. Sunny, with a high near 70.
Night: Areas of fog after 1am. Partly cloudy, with a low around 42.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
64°18°–70°21°
Low, likely
42°6°–47°8°
Typical high / low
74°23° / 45°7°
Wind
8 mph13 km/h, gusts 14 mph22 km/h
UV peak
4
Wednesday, Oct 28. Cloudy. High 67°19°, low 42°6°. Typical 73°23° / 45°7°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 47°9°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 70°21°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 57°14°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 54°12°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Areas of fog before 9am. Partly sunny, with a high near 67.
Night: Areas of fog after 2am. Mostly cloudy, with a low around 42.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
65°18°–73°23°
Low, likely
42°6°–47°8°
Typical high / low
73°23° / 45°7°
Wind
5 mph9 km/h, gusts 15 mph24 km/h
UV peak
4
Thursday, Oct 29. Cloudy. High 65°18°, low 40°4°. Typical 73°23° / 45°7°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 51°10°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 68°20°
  Dry
3. Evening
  6 PM–midnight
  Clear, 55°13°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 45°7°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Areas of fog before 10am. Mostly sunny, with a high near 65.
Night: Areas of fog after 2am. Partly cloudy, with a low around 40.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
64°18°–69°21°
Low, likely
40°4°–51°11°
Typical high / low
73°23° / 45°7°
Wind
8 mph13 km/h, gusts 28 mph45 km/h
UV peak
3
Friday, Oct 30. Rain. High 63°17°, low 38°3°. Typical 72°22° / 45°7°. Rain 0.01 in0.3 mm, 20% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 46°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 65°18°
  Dry
3. Evening
  6 PM–midnight
  Clear, 52°11°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 43°6°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Areas of fog before 10am, then a slight chance of rain. Mostly sunny, with a high near 63.
Night: A slight chance of rain before 1am, then areas of fog and a slight chance of rain. Partly cloudy, with a low around 38.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
60°16°–67°19°
Low, likely
38°3°–45°7°
Typical high / low
72°22° / 45°7°
Wind
10 mph16 km/h, gusts 26 mph42 km/h
UV peak
4
Saturday, Oct 31. Cloudy. High 65°18°, low 42°6°. Typical 72°22° / 45°7°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 43°6°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 66°19°
  Dry
3. Evening
  6 PM–midnight
  Clear, 52°11°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 43°6°
  Dry
Hours this far out come from computer models only.
The National Weather Service writes about seven days ahead; this day is our model forecast only.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
60°16°–71°22°
Low, likely
37°3°–45°7°
Typical high / low
72°22° / 45°7°
Wind
5 mph8 km/h, gusts 20 mph31 km/h
UV peak
4
Sunday, Nov 1. Cloudy. High 68°20°, low 42°6°. Typical 72°22° / 44°7°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 45°7°
  Dry
2. Afternoon
  noon–6 PM
  Mostly sunny, 69°20°
  Dry
3. Evening
  6 PM–midnight
  Clear, 56°13°
  Dry
4. Overnight
  midnight–6 AM
  Drizzle, 44°7°
  Dry
Hours this far out come from computer models only.
The National Weather Service writes about seven days ahead; this day is our model forecast only.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
63°17°–74°23°
Low, likely
37°3°–46°8°
Typical high / low
72°22° / 44°7°
Wind
6 mph9 km/h, gusts 15 mph23 km/h
UV peak
4
Monday, Nov 2. Rain. High 61°16°, low 44°7°. Typical 71°22° / 44°7°. Rain 0.16 in4.1 mm, 20% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Partly sunny, 51°11°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 60°15°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 53°11°
  Dry
Hours this far out come from computer models only.
The National Weather Service writes about seven days ahead; this day is our model forecast only.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
58°14°–65°18°
Low, likely
40°4°–50°10°
Typical high / low
71°22° / 44°7°
Wind
7 mph12 km/h, gusts 23 mph37 km/h

10 days15 days30 days

The outlook

Today
Dry, high 76°, low 44°.
Tomorrow
Dry, high 74°, low 42°.
Monday
Dry, high 69°, low 40°, cooling off.
Rest of week
Mostly dry, highs 61–70°.

Want the meteorologists’ reasoning? Read the NWS forecast discussion (MTR) (opens in a new tab)

What changed since yesterday

No meaningful changes from yesterday’s forecast.

Radar

Radar data: NOAA MRMS, rendered by forecast.blue

Radar loads when scrolled into view

Full-screen radar

Rivers

NOAA river gauges within 25 mi

Napa River near St. Helena

0.7 mi

Below flood stage

Level: 0.5 ft

Forecast peak 1.1 ft Sat 12 PM

Reading from Sat 10:45 AM · NWS gauge page

Napa River near Napa

13 mi

Below flood stage

Level: 2.1 ft
Flow: 2 cfs

Forecast peak 2.1 ft Sat 12 PM

Reading from Sat 10:45 AM · NWS gauge page

Santa Rosa Creek at Santa Rosa

15 mi

Below flood stage

Level: 23.4 ft
Flow: 1 cfs

Forecast peak 23.4 ft Sat 12 PM

Reading from Sat 10 AM · NWS gauge page

Sulphur Creek at Pope Street

0.6 mi

Below flood stage

Level: 1.1 ft

Reading from Sat 10:15 AM · NWS gauge page

For your home

What this week’s weather means for heating, cooling, pipes and fresh air.

Heating this week

About 46% less heating than a typical week.

This week 21Typical 39

Heating degree days, base 65°F

Heat-pump hours, next 7 days

h below 47°F: 14
h below 17°F: 0
h below 5°F: 0

47, 17 and 5°F are the test points heat pumps are rated at.

Comfort

Dry air outside (dew point 44°F).

Open the windows?

Today, 1:00 PM–7:00 PM

Good stretch to open the windows.

Is this typical?

SONOMA · official normals 1991–2020 · records 1893–2026

Oct 24, today vs a typical year

Today’s expected high is about typical for the date.

Last 7 days vs normal

—SunOct 18
—MonOct 19
—TueOct 20
—WedOct 21
—ThuOct 22
—FriOct 23
—SatOct 24

St. Helena weather by month: normals, records, snow and freeze dates

Sun & moon

Sun

Daylight: 10 h 51 min; Losing 2 min 16 s a day; shortest Dec 21, 1 h 23 min less
Golden hour: 5:42–6:35 PM; Morning 7:11–8:04 AM
Blue hour: 6:35–6:46 PM; Morning 7:01–7:11 AM; first light 7:01 AM

Stars tonight? Fair

Mostly clear 6:46 PM–1 AM, but the moon is 99% lit and up.

Moon

Waxing gibbous

97% lit · growing

Today: sets 5:49 AM · rises 5:19 PM
Full moon: Oct 25
New moon: Nov 8

Looking northwest from St. Helena. The highest point on the skyline is about 4,200 ft, 14 mi away.Skyline from USGS elevation data, heights drawn up to 5× taller. Sky, sun and moon as they are now.

1 active weather alert

Coastal Flood Advisory

St. Helena, CA weather

Next 2 hours

Next 48 hours

Days ahead

The outlook

Today

Tomorrow

Monday

Rest of week

What changed since yesterday

Radar

Rivers

Napa River near St. Helena

Napa River near Napa

Santa Rosa Creek at Santa Rosa

Sulphur Creek at Pope Street

For your home

Heating this week

Heat-pump hours, next 7 days

Comfort

Open the windows?

Is this typical?

Oct 24, today vs a typical year

Last 7 days vs normal

Sun & moon

Sun

Stars tonight? Fair

Moon