Coastal Flood Advisory
Ends in 4 days 22 h
When
Until 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 1.5 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)

Model estimate for 4:00 PM PDT (no recent station report)

Alto, CA weather

Sunny and 72°22°.

Forecasts differ

Now 72°22°

Sunny

Wind: Calm; Light through 4 AM
Dew point: 48°9°; Comfortable
UV tomorrow: 4Moderate; Moderate 11 AM–5 PM · peak 4
Air quality: 31Good; Main pollutant: Ozone

No precipitation expected in the next 2 hours.

From forecast models

Next 48 hours

Good hours for

Below 60°16° tonight after 8 PM
Low 49°9° tomorrow at 6 AM
Above 60°16° tomorrow by noon

This afternoonNear 72°22° · Clear
TonightDown to 50°10° by 4 AM · Clear
Tomorrow morningUp to 59°15° by 11 AM · Mostly cloudy
Tomorrow afternoonUp to 69°21° by 5 PM · Mostly cloudy
Tomorrow nightDown to 50°10° by 4 AM · Partly cloudy
Monday morningUp to 62°17° by 11 AM · Partly cloudy
Monday afternoonNear 65°18° · 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 4p	Sunny	72°22° (likely 69°21° to 73°23°)	72°22°	0%	0 mph0 km/h, gusts 5 mph8 km/h	41%	0%	3
Sat 5p	Sunny	72°22° (likely 67°19° to 72°22°)	72°22°	0%	1 mph2 km/h from W, gusts 6 mph9 km/h	44%	0%	2
Sat 6p	Clear	68°20° (likely 64°18° to 68°20°)	68°20°	0%	0 mph0 km/h, gusts 5 mph8 km/h	51%	0%	1
Sat 7p	Clear	65°18° (likely 60°16° to 65°18°)	65°18°	0%	0 mph0 km/h, gusts 4 mph7 km/h	59%	0%	0
Sat 8p	Clear	59°15° (likely 57°14° to 61°16°)	59°15°	0%	0 mph0 km/h, gusts 4 mph6 km/h	65%	6%	0
Sat 9p	Clear	57°14° (likely 55°13° to 59°15°)	57°14°	0%	0 mph0 km/h, gusts 4 mph6 km/h	71%	8%	0
Sat 10p	Clear	56°13° (likely 54°12° to 57°14°)	56°13°	0%	0 mph0 km/h, gusts 4 mph6 km/h	74%	9%	0
Sat 11p	Clear	54°12° (likely 52°11° to 57°14°)	54°12°	0%	0 mph0 km/h, gusts 4 mph6 km/h	79%	7%	0
Sun 12a	Clear	54°12° (likely 51°11° to 56°13°)	54°12°	0%	0 mph0 km/h, gusts 3 mph5 km/h	79%	1%	0
Sun 1a	Clear	53°12° (likely 51°11° to 56°13°)	53°12°	0%	0 mph0 km/h, gusts 3 mph5 km/h	78%	2%	0
Sun 2a	Clear	52°11° (likely 51°11° to 56°13°)	52°11°	0%	0 mph0 km/h, gusts 2 mph4 km/h	79%	5%	0
Sun 3a	Partly cloudy	51°11° (likely 51°11° to 55°13°)	51°11°	0%	0 mph0 km/h, gusts 2 mph3 km/h	81%	39%	0
Sun 4a	Mostly cloudy	50°10° (likely 50°10° to 54°12°)	50°10°	0%	0 mph0 km/h, gusts 2 mph3 km/h	82%	51%	0
Sun 5a	Cloudy	50°10° (likely 50°10° to 53°12°)	50°10°	0%	0 mph0 km/h, gusts 2 mph3 km/h	84%	62%	0
Sun 6a	Cloudy	49°9° (likely 49°9° to 53°12°)	49°9°	0%	0 mph0 km/h, gusts 2 mph4 km/h	84%	71%	0
Sun 7a	Partly sunny	49°9° (likely 49°9° to 53°12°)	49°9°	0%	0 mph0 km/h, gusts 3 mph5 km/h	85%	78%	0
Sun 8a	Cloudy	50°10° (likely 49°9° to 53°12°)	50°10°	0%	0 mph0 km/h, gusts 4 mph6 km/h	86%	83%	0
Sun 9a	Cloudy	53°12° (likely 51°11° to 56°13°)	53°12°	0%	1 mph2 km/h from NNE, gusts 4 mph6 km/h	85%	83%	1
Sun 10a	Cloudy	57°14° (likely 56°13° to 62°17°)	57°14°	0%	1 mph2 km/h from NE, gusts 5 mph8 km/h	79%	80%	2
Sun 11a	Cloudy	59°15° (likely 59°15° to 66°19°)	59°15°	0%	2 mph3 km/h from E, gusts 5 mph9 km/h	72%	80%	3
Sun 12p	Cloudy	62°17° (likely 62°17° to 69°21°)	62°17°	0%	1 mph2 km/h from SSE, gusts 6 mph9 km/h	67%	63%	4
Sun 1p	Cloudy	64°18° (likely 64°18° to 69°21°)	65°18°	0%	1 mph2 km/h from SSW, gusts 8 mph12 km/h	60%	83%	4
Sun 2p	Cloudy	67°19° (likely 66°19° to 69°21°)	67°19°	0%	1 mph2 km/h from SW, gusts 9 mph15 km/h	54%	83%	4
Sun 3p	Cloudy	68°20° (likely 67°19° to 68°20°)	68°20°	0%	1 mph2 km/h from SW, gusts 12 mph19 km/h	54%	84%	3
Sun 4p	Cloudy	68°20° (likely 65°18° to 68°20°)	68°20°	0%	0 mph0 km/h, gusts 12 mph19 km/h	54%	87%	3
Sun 5p	Cloudy	69°21° (likely 64°18° to 69°21°)	69°21°	0%	0 mph0 km/h, gusts 12 mph20 km/h	54%	87%	1
Sun 6p	Cloudy	66°19° (likely 61°16° to 66°19°)	66°19°	0%	0 mph0 km/h, gusts 12 mph20 km/h	61%	90%	0
Sun 7p	Partly cloudy	63°17° (likely 59°15° to 63°17°)	63°17°	0%	0 mph0 km/h, gusts 11 mph18 km/h	69%	79%	0
Sun 8p	Cloudy	60°16° (likely 56°13° to 60°16°)	60°16°	0%	0 mph0 km/h, gusts 8 mph14 km/h	75%	90%	0
Sun 9p	Mostly clear	56°13° (likely 54°12° to 57°14°)	56°13°	0%	0 mph0 km/h, gusts 7 mph11 km/h	81%	36%	0
Sun 10p	Mostly clear	55°13° (likely 52°11° to 56°13°)	55°13°	0%	0 mph0 km/h, gusts 7 mph11 km/h	85%	14%	0
Sun 11p	Clear	54°12° (likely 51°11° to 56°13°)	54°12°	0%	0 mph0 km/h, gusts 7 mph12 km/h	87%	8%	0
Mon 12a	Clear	53°12° (likely 51°11° to 55°13°)	53°12°	0%	0 mph0 km/h, gusts 9 mph15 km/h	87%	9%	0
Mon 1a	Clear	53°12° (likely 50°10° to 55°13°)	53°12°	0%	0 mph0 km/h, gusts 11 mph17 km/h	86%	8%	0
Mon 2a	Clear	52°11° (likely 50°10° to 55°13°)	52°11°	0%	2 mph3 km/h from W, gusts 13 mph21 km/h	86%	15%	0
Mon 3a	Clear	51°11° (likely 50°10° to 55°13°)	51°11°	0%	2 mph3 km/h from W, gusts 13 mph21 km/h	87%	15%	0
Mon 4a	Clear	50°10° (likely 50°10° to 55°13°)	51°11°	0%	2 mph3 km/h from W, gusts 14 mph22 km/h	88%	15%	0
Mon 5a	Clear	50°10° (likely 49°9° to 55°13°)	50°10°	0%	2 mph3 km/h from W, gusts 14 mph23 km/h	89%	17%	0
Mon 6a	Clear	50°10° (likely 49°9° to 54°12°)	50°10°	0%	2 mph3 km/h from W, gusts 14 mph23 km/h	89%	11%	0
Mon 7a	Sunny	50°10° (likely 49°9° to 54°12°)	50°10°	0%	2 mph3 km/h from W, gusts 14 mph23 km/h	90%	14%	0
Mon 8a	Sunny	51°11° (likely 50°10° to 55°13°)	50°10°	0%	3 mph5 km/h from WNW, gusts 11 mph18 km/h	90%	20%	0
Mon 9a	Mostly sunny	54°12° (likely 54°12° to 57°14°)	54°12°	0%	3 mph5 km/h from WNW, gusts 11 mph18 km/h	88%	19%	1
Mon 10a	Sunny	58°14° (likely 58°14° to 62°17°)	58°14°	0%	3 mph5 km/h from WNW, gusts 12 mph20 km/h	83%	35%	2
Mon 11a	Mostly sunny	62°17° (likely 62°17° to 65°18°)	62°17°	0%	6 mph10 km/h from W, gusts 13 mph22 km/h	78%	52%	3
Mon 12p	Mostly sunny	64°18° (likely 64°18° to 66°19°)	64°18°	0%	6 mph10 km/h from W, gusts 14 mph23 km/h	73%	27%	4
Mon 1p	Mostly sunny	65°18° (likely 64°18° to 67°19°)	65°18°	0%	6 mph10 km/h from W, gusts 15 mph24 km/h	69%	34%	5
Mon 2p	Mostly sunny	66°19° (likely 65°18° to 67°19°)	66°19°	0%	10 mph16 km/h from W, gusts 16 mph26 km/h	65%	29%	5
Mon 3p	Mostly sunny	66°19° (likely 64°18° to 66°19°)	66°19°	0%	10 mph16 km/h from W, gusts 17 mph27 km/h	62%	17%	4

Days ahead

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

Today, Oct 24. Sunny. High 73°23°, low 48°9°. Typical 69°21° / 54°12°. Dry. Forecasts differ.
1. Afternoon
  noon–6 PM
  Sunny, 72°22°
  Dry
2. Evening
  6 PM–midnight
  Clear, 59°15°
  Dry
3. Overnight
  midnight–6 AM
  Partly cloudy, 50°10°
  Dry
Official NWS forecast
Today: Sunny, with a high near 73. West southwest wind around 1 mph.
Tonight: Mostly clear. Low around 48, with temperatures rising to around 50 overnight. Wind around 0 mph.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
68°20°–75°24°
Low, likely
48°9°–52°11°
Typical high / low
69°21° / 54°12°
Wind
6 mph10 km/h
UV peak
5
Tomorrow, Oct 25. Cloudy. High 70°21°, low 49°9°. Typical 69°21° / 54°12°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Cloudy, 50°10°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 69°21°
  Dry
3. Evening
  6 PM–midnight
  Mostly clear, 60°16°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 50°10°
  Dry
Official NWS forecast
Day: Partly sunny, with a high near 70. South wind around 2 mph.
Night: Partly cloudy, with a low around 49. West northwest wind around 2 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
67°19°–70°21°
Low, likely
49°9°–52°11°
Typical high / low
69°21° / 54°12°
Wind
11 mph18 km/h, gusts 18 mph28 km/h
UV peak
4
Monday, Oct 26. Mostly sunny. High 67°19°, low 47°8°. Typical 69°21° / 54°12°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Mostly sunny, 51°11°
  Dry
2. Afternoon
  noon–6 PM
  Mostly sunny, 66°19°
  Dry
3. Evening
  6 PM–midnight
  Clear, 56°13°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 49°9°
  Dry
Official NWS forecast
Day: Sunny, with a high near 67. West wind 2 to 10 mph.
Night: Mostly clear, with a low around 47.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
64°18°–67°19°
Low, likely
47°8°–54°12°
Typical high / low
69°21° / 54°12°
Wind
11 mph17 km/h, gusts 22 mph36 km/h
UV peak
5
Tuesday, Oct 27. Mostly sunny. High 66°19°, low 48°9°. Typical 69°21° / 53°12°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Cloudy, 48°9°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 64°18°
  Dry
3. Evening
  6 PM–midnight
  Mostly clear, 55°13°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 49°10°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Sunny, with a high near 66.
Night: Partly cloudy, with a low around 48.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
62°17°–66°19°
Low, likely
47°8°–51°11°
Typical high / low
69°21° / 53°12°
Wind
11 mph18 km/h, gusts 22 mph35 km/h
UV peak
5
Wednesday, Oct 28. Mostly cloudy. High 63°17°, low 50°10°. Typical 68°20° / 53°12°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Cloudy, 49°9°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 63°17°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 56°13°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 55°13°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Partly sunny, with a high near 63.
Night: Mostly cloudy, with a low around 50.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
61°16°–65°18°
Low, likely
46°8°–51°11°
Typical high / low
68°20° / 53°12°
Wind
8 mph13 km/h, gusts 20 mph32 km/h
UV peak
4
Thursday, Oct 29. Cloudy. High 62°17°, low 48°9°. Typical 68°20° / 53°12°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Cloudy, 54°12°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 64°18°
  Dry
3. Evening
  6 PM–midnight
  Clear, 55°13°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 49°9°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Mostly sunny, with a high near 62.
Night: A slight chance of rain after 5am. Partly cloudy, with a low around 48.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
61°16°–64°18°
Low, likely
48°9°–53°12°
Typical high / low
68°20° / 53°12°
Wind
9 mph15 km/h, gusts 23 mph37 km/h
UV peak
4
Friday, Oct 30. Rain. High 62°17°, low 47°8°. Typical 68°20° / 53°12°. Rain 0.01 in0.3 mm, 20% chance. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 48°9°
  Dry
2. Afternoon
  noon–6 PM
  Mostly sunny, 62°17°
  Dry
3. Evening
  6 PM–midnight
  Clear, 54°12°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 48°9°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: A slight chance of rain. Mostly sunny, with a high near 62.
Night: A slight chance of rain. Partly cloudy, with a low around 47.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
60°16°–63°17°
Low, likely
46°8°–51°11°
Typical high / low
68°20° / 53°12°
Wind
12 mph20 km/h, gusts 27 mph44 km/h
UV peak
4
Saturday, Oct 31. Cloudy. High 61°16°, low 49°9°. Typical 68°20° / 53°12°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 48°9°
  Dry
2. Afternoon
  noon–6 PM
  Mostly sunny, 62°17°
  Dry
3. Evening
  6 PM–midnight
  Clear, 54°12°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 49°9°
  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.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
58°14°–65°18°
Low, likely
45°7°–51°11°
Typical high / low
68°20° / 53°12°
Wind
9 mph15 km/h, gusts 20 mph32 km/h
UV peak
4
Sunday, Nov 1. Drizzle. High 63°17°, low 48°9°. Typical 68°20° / 53°12°. Rain 0.02 in0.5 mm, 10% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 49°9°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 64°18°
  Dry
3. Evening
  6 PM–midnight
  Drizzle, 58°15°
  Dry
4. Overnight
  midnight–6 AM
  Drizzle, 51°10°
  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°–68°20°
Low, likely
45°7°–50°10°
Typical high / low
68°20° / 53°12°
Wind
12 mph19 km/h, gusts 17 mph27 km/h
UV peak
4
Monday, Nov 2. Cloudy. High 58°14°, low 50°10°. Typical 67°19° / 53°12°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Cloudy, 52°11°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 56°13°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 55°13°
  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.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
56°13°–61°16°
Low, likely
48°9°–52°11°
Typical high / low
67°19° / 53°12°
Wind
13 mph21 km/h

10 days15 days30 days

The outlook

Today
Dry, high 73°, low 48°.
Tomorrow
Dry, high 70°, low 49°, cooling off.
Monday
Dry, high 67°, low 47°, cooling off.
Rest of week
Mostly dry, highs 58–66°.

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

Arroyo Corte Madera del Presidio

1.1 mi

Below flood stage

Level: 2.8 ft

Reading from Sat 11:05 AM · NWS gauge page

Coyote Creek (Marin) at Tam Valley

1.9 mi

Below flood stage

Level: 3.3 ft

Reading from Sat 2:50 PM · NWS gauge page

Redwood Creek (Marin County) above Highway 1 Bridge at Muir Beach

4.3 mi

Below flood stage

Level: 1.1 ft
Flow: 1 cfs

Reading from Sat 2:30 PM · NWS gauge page

Corte Madera Creek at Ross

4.5 mi

Below flood stage

Level: 4.2 ft
Flow: 1 cfs

Reading from Sat 2:30 PM · NWS gauge page

For your home

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

Heating this week

About 44% less heating than a typical week.

This week 16Typical 28

Heating degree days, base 65°F

Comfort

Dry air outside (dew point 48°F).

Open the windows?

Today, 5:00 PM–7:00 PM

Good stretch to open the windows.

Is this typical?

San Francisco Downtown · official normals 1991–2020 · records 1874–2026

Oct 24, today vs a typical year

Today’s expected high is 4°2° warmer than typical.

Last 7 days vs normal

On average 1° colder than normal (daily mean temperature).

−3°−2°SunOct 18
−2°−1°MonOct 19
−1°TueOct 20
+1°WedOct 21
−2°−1°ThuOct 22
±0°FriOct 23
—SatOct 24

Alto weather by month: normals, records, snow and freeze dates

Sun & moon

Sun

Daylight: 10 h 53 min; Losing 2 min 16 s a day; shortest Dec 21, 1 h 21 min less
Golden hour: 5:44–6:36 PM; Morning 7:11–8:03 AM
Blue hour: 6:36–6:47 PM; Morning 7:00–7:11 AM; first light 7:00 AM

Stars tonight? Fair

Mostly clear 6:47 PM–3 AM, but the moon is 99% lit and up.

Moon

Waxing gibbous

98% lit · growing

Today: sets 5:49 AM · rises 5:20 PM
Full moon: Oct 25
New moon: Nov 8

Looking west from Alto. The highest point on the skyline is about 2,500 ft, 4 mi away.Skyline from USGS elevation data, heights drawn up to 3× taller. Sky, sun and moon as they are now.

1 active weather alert

Coastal Flood Advisory

Alto, CA weather

Next 2 hours

Next 48 hours

Days ahead

The outlook

Today

Tomorrow

Monday

Rest of week

What changed since yesterday

Radar

Rivers

Arroyo Corte Madera del Presidio

Coyote Creek (Marin) at Tam Valley

Redwood Creek (Marin County) above Highway 1 Bridge at Muir Beach

Corte Madera Creek at Ross

For your home

Heating this week

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