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)

Observed 3:35 PM PDT at KHWD

Union City, CA weather

Sunny and 72°22°.

Mostly agree

Now 72°22°

Sunny

Wind: 12 mph19 km/h; From the west. Up to 12 mph19 km/h through 4 AM
Dew point: 43°6°; Comfortable · up to 51°11° by 6 PM
UV tomorrow: 5Moderate; Moderate 11 AM–4 PM · peak 5
Air quality: 31Good; Main pollutant: Ozone
Pressure: 29.98 inHg1015 hPa; Falling slowly · −0.04 inHg−1.4 hPa in 3 h

No precipitation expected in the next 2 hours.

From forecast models

Next 48 hours

Good hours for

High 70°21° today at 5 PM
Below 60°16° tonight after 9 PM
Low 51°11° tomorrow at 6 AM
Above 60°16° tomorrow by 11 AM

This afternoonNear 70°21° · Clear
TonightDown to 52°11° by 4 AM · Clear
Tomorrow morningUp to 62°17° by 11 AM · Mostly cloudy
Tomorrow afternoonUp to 70°21° by 3 PM · Mostly cloudy
Tomorrow nightDown to 52°11° by 5 AM · Partly cloudy
Monday morningUp to 60°16° by 11 AM · Mostly cloudy
Monday afternoonNear 64°18° · Clear

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	69°21° (likely 69°21° to 71°22°)	69°21°	0%	5 mph8 km/h from WNW, gusts 7 mph12 km/h	48%	0%	2
Sat 5p	Sunny	70°21° (likely 68°20° to 71°22°)	70°21°	0%	5 mph8 km/h from WNW, gusts 8 mph13 km/h	49%	0%	2
Sat 6p	Clear	67°19° (likely 64°18° to 67°19°)	67°19°	0%	3 mph5 km/h from NW, gusts 10 mph16 km/h	58%	0%	1
Sat 7p	Clear	63°17° (likely 60°16° to 63°17°)	63°17°	0%	2 mph3 km/h from NW, gusts 8 mph13 km/h	65%	0%	0
Sat 8p	Clear	61°16° (likely 57°14° to 61°16°)	61°16°	0%	1 mph2 km/h from NNW, gusts 6 mph10 km/h	68%	0%	0
Sat 9p	Clear	58°14° (likely 54°12° to 58°14°)	58°14°	0%	0 mph0 km/h, gusts 6 mph10 km/h	69%	0%	0
Sat 10p	Clear	57°14° (likely 52°11° to 57°14°)	57°14°	0%	1 mph2 km/h from N, gusts 5 mph9 km/h	69%	0%	0
Sat 11p	Clear	56°13° (likely 50°10° to 56°13°)	56°13°	0%	2 mph3 km/h from ENE, gusts 4 mph7 km/h	71%	0%	0
Sun 12a	Clear	55°13° (likely 48°9° to 55°13°)	55°13°	0%	2 mph3 km/h from E, gusts 5 mph8 km/h	71%	0%	0
Sun 1a	Clear	55°13° (likely 47°8° to 55°13°)	55°13°	0%	2 mph3 km/h from E, gusts 5 mph8 km/h	69%	0%	0
Sun 2a	Clear	54°12° (likely 46°8° to 54°12°)	54°12°	0%	2 mph3 km/h from E, gusts 4 mph6 km/h	69%	0%	0
Sun 3a	Clear	53°12° (likely 46°8° to 53°12°)	53°12°	0%	2 mph3 km/h from E, gusts 4 mph6 km/h	71%	7%	0
Sun 4a	Mostly clear	52°11° (likely 45°7° to 52°11°)	52°11°	0%	2 mph3 km/h from E, gusts 4 mph6 km/h	70%	22%	0
Sun 5a	Partly cloudy	52°11° (likely 44°7° to 52°11°)	52°11°	0%	2 mph3 km/h from E, gusts 4 mph6 km/h	71%	51%	0
Sun 6a	Partly cloudy	51°11° (likely 44°7° to 51°11°)	51°11°	0%	2 mph3 km/h from E, gusts 3 mph5 km/h	73%	54%	0
Sun 7a	Cloudy	51°11° (likely 43°6° to 51°11°)	51°11°	0%	1 mph2 km/h from ENE, gusts 4 mph6 km/h	72%	58%	0
Sun 8a	Partly sunny	51°11° (likely 43°6° to 51°11°)	51°11°	0%	1 mph2 km/h from NE, gusts 4 mph6 km/h	76%	73%	0
Sun 9a	Partly sunny	55°13° (likely 48°9° to 55°13°)	55°13°	0%	1 mph2 km/h from E, gusts 3 mph5 km/h	74%	76%	1
Sun 10a	Cloudy	59°15° (likely 57°14° to 60°16°)	59°15°	0%	0 mph0 km/h, gusts 3 mph5 km/h	72%	72%	2
Sun 11a	Cloudy	62°17° (likely 62°17° to 64°18°)	62°17°	0%	1 mph2 km/h from SW, gusts 3 mph5 km/h	68%	70%	3
Sun 12p	Mostly cloudy	66°19° (likely 66°19° to 68°20°)	66°19°	0%	2 mph3 km/h from WSW, gusts 3 mph6 km/h	64%	66%	4
Sun 1p	Mostly cloudy	68°20° (likely 68°20° to 70°21°)	68°20°	0%	3 mph5 km/h from W, gusts 5 mph9 km/h	61%	73%	5
Sun 2p	Cloudy	69°21° (likely 69°21° to 71°22°)	69°21°	0%	5 mph8 km/h from W, gusts 7 mph11 km/h	58%	84%	4
Sun 3p	Cloudy	70°21° (likely 69°21° to 71°22°)	70°21°	0%	6 mph10 km/h from WNW, gusts 10 mph16 km/h	56%	80%	3
Sun 4p	Cloudy	69°21° (likely 67°19° to 70°21°)	69°21°	0%	7 mph11 km/h from WNW, gusts 12 mph20 km/h	56%	81%	2
Sun 5p	Partly sunny	69°21° (likely 64°18° to 69°21°)	69°21°	0%	7 mph11 km/h from WNW, gusts 12 mph20 km/h	58%	86%	1
Sun 6p	Cloudy	66°19° (likely 61°16° to 66°19°)	66°19°	0%	6 mph10 km/h from WNW, gusts 12 mph20 km/h	66%	82%	0
Sun 7p	Cloudy	61°16° (likely 58°14° to 61°16°)	61°16°	0%	3 mph5 km/h from WNW, gusts 11 mph18 km/h	74%	89%	0
Sun 8p	Partly cloudy	59°15° (likely 56°13° to 59°15°)	59°15°	0%	2 mph3 km/h from WNW, gusts 10 mph16 km/h	78%	85%	0
Sun 9p	Mostly cloudy	58°14° (likely 55°13° to 58°14°)	58°14°	0%	2 mph3 km/h from WNW, gusts 9 mph15 km/h	81%	69%	0
Sun 10p	Partly cloudy	57°14° (likely 54°12° to 57°14°)	57°14°	0%	2 mph3 km/h from WNW, gusts 8 mph13 km/h	83%	31%	0
Sun 11p	Clear	56°13° (likely 52°11° to 56°13°)	56°13°	0%	2 mph3 km/h from W, gusts 6 mph10 km/h	85%	7%	0
Mon 12a	Clear	55°13° (likely 51°11° to 55°13°)	55°13°	0%	2 mph3 km/h from W, gusts 5 mph8 km/h	87%	10%	0
Mon 1a	Partly cloudy	55°13° (likely 49°9° to 55°13°)	55°13°	0%	2 mph3 km/h from W, gusts 6 mph10 km/h	86%	33%	0
Mon 2a	Mostly clear	54°12° (likely 49°9° to 54°12°)	54°12°	0%	2 mph3 km/h from WSW, gusts 7 mph11 km/h	86%	52%	0
Mon 3a	Cloudy	53°12° (likely 50°10° to 54°12°)	53°12°	0%	2 mph3 km/h from WSW, gusts 7 mph11 km/h	87%	95%	0
Mon 4a	Mostly cloudy	53°12° (likely 51°11° to 54°12°)	53°12°	0%	2 mph3 km/h from WSW, gusts 7 mph11 km/h	87%	72%	0
Mon 5a	Partly cloudy	52°11° (likely 50°10° to 54°12°)	52°11°	0%	2 mph3 km/h from WSW, gusts 6 mph10 km/h	88%	64%	0
Mon 6a	Partly cloudy	52°11° (likely 48°9° to 53°12°)	52°11°	0%	2 mph3 km/h from WSW, gusts 5 mph8 km/h	90%	59%	0
Mon 7a	Mostly cloudy	52°11° (likely 47°8° to 53°12°)	52°11°	0%	2 mph3 km/h from WSW, gusts 5 mph8 km/h	92%	66%	0
Mon 8a	Partly sunny	52°11° (likely 48°9° to 53°12°)	52°11°	0%	2 mph3 km/h from SW, gusts 5 mph8 km/h	93%	82%	0
Mon 9a	Mostly cloudy	54°12° (likely 52°11° to 56°13°)	54°12°	0%	2 mph3 km/h from SW, gusts 5 mph8 km/h	94%	67%	1
Mon 10a	Mostly cloudy	57°14° (likely 56°13° to 59°15°)	57°14°	0%	2 mph3 km/h from SW, gusts 7 mph12 km/h	93%	68%	2
Mon 11a	Partly sunny	60°16° (likely 60°16° to 62°17°)	60°16°	0%	3 mph5 km/h from W, gusts 9 mph14 km/h	91%	49%	3
Mon 12p	Sunny	62°17° (likely 62°17° to 66°19°)	62°17°	0%	3 mph5 km/h from W, gusts 11 mph17 km/h	88%	23%	4
Mon 1p	Partly sunny	64°18° (likely 64°18° to 67°19°)	64°18°	0%	3 mph5 km/h from W, gusts 11 mph18 km/h	84%	23%	5
Mon 2p	Partly sunny	64°18° (likely 64°18° to 68°20°)	65°18°	0%	9 mph14 km/h from W, gusts 13 mph21 km/h	79%	14%	5
Mon 3p	Sunny	65°18° (likely 65°18° to 68°20°)	65°18°	0%	9 mph14 km/h from W, gusts 14 mph23 km/h	76%	5%	4

Days ahead

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

Today, Oct 24. Sunny. High 70°21°, low 51°11°. Typical 72°22° / 52°11°. Dry. Mostly agree.
1. Afternoon
  noon–6 PM
  Sunny, 70°21°
  Dry
2. Evening
  6 PM–midnight
  Clear, 61°16°
  Dry
3. Overnight
  midnight–6 AM
  Clear, 52°11°
  Dry
Official NWS forecast
Today: Sunny, with a high near 70. West northwest wind around 5 mph.
Tonight: Mostly clear, with a low around 51. North northeast wind 0 to 3 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
69°21°–72°22°
Low, likely
43°6°–51°11°
Typical high / low
72°22° / 52°11°
Wind
9 mph14 km/h, gusts 15 mph24 km/h
UV peak
5
Tomorrow, Oct 25. Partly sunny. High 71°22°, low 51°11°. Typical 72°22° / 51°11°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Partly sunny, 51°11°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 70°21°
  Dry
3. Evening
  6 PM–midnight
  Mostly cloudy, 59°15°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 52°11°
  Dry
Official NWS forecast
Day: Mostly sunny. High near 71, with temperatures falling to around 69 in the afternoon. West wind 0 to 7 mph.
Night: Partly cloudy, with a low around 51. West wind 2 to 6 mph.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
69°21°–71°22°
Low, likely
43°6°–51°11°
Typical high / low
72°22° / 51°11°
Wind
10 mph17 km/h, gusts 16 mph25 km/h
UV peak
5
Monday, Oct 26. Cloudy. High 66°19°, low 50°10°. Typical 72°22° / 51°11°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Mostly cloudy, 52°11°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 65°18°
  Dry
3. Evening
  6 PM–midnight
  Clear, 58°14°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 51°11°
  Dry
Official NWS forecast
Day: Mostly sunny, with a high near 66. West southwest wind 2 to 12 mph, with gusts as high as 18 mph.
Night: Partly cloudy, with a low around 50.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
65°18°–67°19°
Low, likely
47°8°–53°12°
Typical high / low
72°22° / 51°11°
Wind
11 mph17 km/h, gusts 21 mph33 km/h
UV peak
5
Tuesday, Oct 27. Cloudy. High 65°18°, low 49°9°. Typical 72°22° / 51°11°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Cloudy, 51°11°
  Dry
2. Afternoon
  noon–6 PM
  Partly sunny, 65°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: Patchy fog between 8am and 10am. Mostly sunny, with a high near 65.
Night: Partly cloudy, with a low around 49.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
62°17°–67°19°
Low, likely
46°8°–53°12°
Typical high / low
72°22° / 51°11°
Wind
9 mph14 km/h, gusts 20 mph32 km/h
UV peak
5
Wednesday, Oct 28. Mostly cloudy. High 62°17°, low 51°11°. Typical 72°22° / 51°11°. Dry. Mostly agree.
1. Morning
  6 AM–noon
  Cloudy, 48°9°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 65°19°
  Dry
3. Evening
  6 PM–midnight
  Cloudy, 57°14°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 52°11°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: Partly sunny, with a high near 62.
Night: Mostly cloudy, with a low around 51.
Mostly agreeIndependent forecasts are fairly close; small surprises are possible.
High, likely
62°17°–67°19°
Low, likely
43°6°–51°11°
Typical high / low
72°22° / 51°11°
Wind
8 mph12 km/h, gusts 16 mph26 km/h
UV peak
4
Thursday, Oct 29. Cloudy. High 61°16°, low 48°9°. Typical 71°22° / 50°10°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Cloudy, 52°11°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 65°18°
  Dry
3. Evening
  6 PM–midnight
  Partly cloudy, 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: Partly sunny, with a high near 61.
Night: Partly cloudy, with a low around 48.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
61°16°–68°20°
Low, likely
46°8°–55°13°
Typical high / low
71°22° / 50°10°
Wind
9 mph14 km/h, gusts 17 mph27 km/h
UV peak
4
Friday, Oct 30. Rain. High 59°15°, low 47°8°. Typical 71°22° / 50°10°. Rain 0.01 in0.3 mm, 20% chance. Mostly agree.
1. Morning
  6 AM–noon
  Sunny, 49°9°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 63°17°
  Dry
3. Evening
  6 PM–midnight
  Clear, 53°12°
  Dry
4. Overnight
  midnight–6 AM
  Cloudy, 46°8°
  Dry
Hours this far out come from computer models only.
Official NWS forecast
Day: A slight chance of rain after 11am. Mostly sunny, with a high near 59.
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
59°15°–65°18°
Low, likely
43°6°–51°11°
Typical high / low
71°22° / 50°10°
Wind
10 mph16 km/h, gusts 24 mph38 km/h
UV peak
4
Saturday, Oct 31. Cloudy. High 62°17°, low 45°7°. Typical 71°22° / 50°10°. Dry. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 46°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 63°17°
  Dry
3. Evening
  6 PM–midnight
  Clear, 53°12°
  Dry
4. Overnight
  midnight–6 AM
  Clear, 45°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
59°15°–67°19°
Low, likely
36°2°–50°10°
Typical high / low
71°22° / 50°10°
Wind
7 mph11 km/h, gusts 19 mph31 km/h
UV peak
4
Sunday, Nov 1. Drizzle. High 65°18°, low 44°7°. Typical 70°21° / 50°10°. Rain 0.04 in1 mm, 20% chance. Forecasts differ.
1. Morning
  6 AM–noon
  Sunny, 46°8°
  Dry
2. Afternoon
  noon–6 PM
  Sunny, 66°19°
  Dry
3. Evening
  6 PM–midnight
  Drizzle, 57°14°
  Dry
4. Overnight
  midnight–6 AM
  Rain, 48°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.
Forecasts differIndependent forecasts disagree; expect changes and plan for the range.
High, likely
60°16°–71°22°
Low, likely
33°1°–51°11°
Typical high / low
70°21° / 50°10°
Wind
8 mph12 km/h, gusts 20 mph32 km/h
UV peak
4
Monday, Nov 2. Cloudy. High 61°16°, low 48°9°. Typical 70°21° / 49°9°. Dry. Forecasts agree.
1. Morning
  6 AM–noon
  Cloudy, 52°11°
  Dry
2. Afternoon
  noon–6 PM
  Cloudy, 61°16°
  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.
Forecasts agreeIndependent forecasts are close; the range is narrow.
High, likely
60°16°–63°17°
Low, likely
41°5°–54°12°
Typical high / low
70°21° / 49°9°
Wind
6 mph10 km/h, gusts 16 mph26 km/h
UV peak
3

10 days15 days30 days

The outlook

Today
Dry, high 70°, low 51°.
Tomorrow
Dry, high 71°, low 51°.
Monday
Dry, high 66°, low 50°, cooling off.
Rest of week
Mostly dry, highs 59–65°.

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

Alameda Creek near Niles

3.4 mi

Below flood stage

Level: 2.8 ft
Flow: 20 cfs

Forecast peak 2.8 ft Sat 4 PM

Reading from Sat 2 PM · NWS gauge page

San Lorenzo Creek (Alameda) above Hayward

6.2 mi

Below flood stage

Level: 2.6 ft
Flow: under 1 cfs

Forecast peak 2.6 ft Sat 4 PM

Reading from Sat 2:35 PM · NWS gauge page

Arroyo de la Laguna at Verona

7.6 mi

Below flood stage

Level: 0.9 ft
Flow: 12 cfs

Forecast peak 0.9 ft Sat 4 PM

Reading from Sat 2:30 PM · NWS gauge page

Dry Creek at Union City

0.4 mi

Level: 0.6 ft

Reading from Sat 2:15 PM · NWS gauge page

For your home

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

Heating this week

About 47% less heating than a typical week.

This week 14Typical 26

Heating degree days, base 65°F

Comfort

Dry air outside (dew point 43°F).

Open the windows?

Today, 5:00 PM–8:00 PM

Good stretch to open the windows.

Is this typical?

MOFFETT FEDERAL AIRFIELD · official normals 1991–2020 · records 1945–2026

Oct 24, today vs a typical year

Today’s expected high is 2°1° colder than typical.

Last 7 days vs normal

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

Union City 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 20 min less
Golden hour: 5:42–6:35 PM; Morning 7:08–8:01 AM
Blue hour: 6:35–6:45 PM; Morning 6:58–7:08 AM; first light 6:58 AM

Stars tonight? Fair

Clear 6:45 PM–5 AM, but the moon is 99% lit and up.

Moon

Waxing gibbous

98% lit · growing

Today: sets 5:46 AM · rises 5:18 PM
Full moon: Oct 25
New moon: Nov 8

Looking east from Union City. The highest point on the skyline is about 3,800 ft, 21 mi away.Skyline from USGS elevation data, heights drawn up to 3.5× taller. Sky, sun and moon as they are now.

1 active weather alert

Coastal Flood Advisory

Union City, CA weather

Next 2 hours

Next 48 hours

Days ahead

The outlook

Today

Tomorrow

Monday

Rest of week

What changed since yesterday

Radar

Rivers

Alameda Creek near Niles

San Lorenzo Creek (Alameda) above Hayward

Arroyo de la Laguna at Verona

Dry Creek at Union City

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