Hourly Weather | Today › Friday, October 9, 2026
Active Weather Warnings
San Marcos, California
10 PM
Cloudy Night
68°
Feels Like 68°
0
Humidity: 87%
UV Index: 0
Wind: 5 mph
11 PM
Cloudy Night
66°
Feels Like 66°
0
Humidity: 90%
UV Index: 0
Wind: 5 mph

Hourly Air Quality Forecast - AQI (US EPA)

10 PM
46 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 10.72 µg/m³
  • PM10: 24.38 µg/m³
  • O3: 0.050 ppm
  • NO2: 0.2 ppb
  • SO2: 0.2 ppb
  • CO: 0.10 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

11 PM
46 AQI
Good air quality Dominant pollutant: O3
Details

Pollutant Concentrations:

  • PM2.5: 10.64 µg/m³
  • PM10: 24.28 µg/m³
  • O3: 0.050 ppm
  • NO2: 0.3 ppb
  • SO2: 0.2 ppb
  • CO: 0.10 ppm

Health Recommendations:

Air quality is considered satisfactory, and air pollution poses little or no risk.

Weather Alerts and Warnings for San Marcos

Severe Future Possible

Tropical Storm Watch

Tropical Storm Watch issued October 9 at 1:57PM PDT by NWS San Diego CA
Oct 9, 1:57 PM → Oct 9, 10:00 PM
* LOCATIONS AFFECTED
- Escondido
- El Cajon
- Lakeside
- Poway

* WIND
- LATEST LOCAL FORECAST: Below tropical storm force wind
- Peak Wind Forecast: 20-30 mph with gusts to 45 mph

- THREAT TO LIFE AND PROPERTY THAT INCLUDES TYPICAL FORECAST
UNCERTAINTY IN TRACK, SIZE AND INTENSITY: Potential for wind 39
to 57 mph
- The wind threat has remained nearly steady from the
previous assessment.
- PLAN: Plan for hazardous wind of equivalent tropical storm
force.
- PREPARE: Efforts to protect property should now be
underway. Prepare for limited wind damage.
- ACT: Act now to complete preparations before the wind
becomes hazardous.

- POTENTIAL IMPACTS: Limited
- Damage to porches, awnings, carports, sheds, and unanchored
mobile homes. Unsecured lightweight objects blown about.
- Many large tree limbs broken off. A few trees snapped or
uprooted, but with greater numbers in places where trees
are shallow rooted, especially in coastal and valley
locations that don't typically experience strong winds.
Some fences and roadway signs blown over.
- A few roads impassable from debris, particularly within
urban or heavily wooded places. Hazardous driving
conditions on bridges and other elevated roadways.
- Scattered power and communications outages.

* FLOODING RAIN
- LATEST LOCAL FORECAST: Flood Watch is in effect
- Peak Rainfall Amounts: around 1 inch

- THREAT TO LIFE AND PROPERTY THAT INCLUDES TYPICAL FORECAST
UNCERTAINTY IN TRACK, SIZE AND INTENSITY: Potential for major
flooding rain
- The flooding rain threat has remained nearly steady from
the previous assessment.
- PLAN: Emergency plans should include the potential for
major flooding from heavy rain. Evacuations and rescues are
likely.
- PREPARE: Strongly consider protective actions, especially
if you are in an area vulnerable to flooding.
- ACT: Heed any flood watches and warnings. Failure to take
action will likely result in serious injury or loss of life.

- POTENTIAL IMPACTS: Extensive
- Major rainfall flooding may prompt many evacuations and
rescues.
- Rivers and tributaries may rapidly overflow their banks in
multiple places. Small streams, creeks, canals, arroyos,
and ditches may become dangerous rivers. In mountain areas,
destructive runoff may run quickly down valleys while
increasing susceptibility to rockslides and mudslides.
Flood control systems and barriers may become stressed.
- Flood waters can enter many structures within multiple
communities, some structures becoming uninhabitable or
washed away. Many places where flood waters may cover
escape routes. Streets and parking lots become rivers of
moving water with underpasses submerged. Driving conditions
become dangerous. Many road and bridge closures with some
weakened or washed out.

* TORNADO
- LATEST LOCAL FORECAST:
- Situation is unfavorable for tornadoes

- THREAT TO LIFE AND PROPERTY THAT INCLUDES TYPICAL FORECAST
UNCERTAINTY IN TRACK, SIZE AND INTENSITY: Tornadoes not expected
- The tornado threat has remained nearly steady from the
previous assessment.
- PLAN: Tornadoes are not expected. Showers and thunderstorms
with gusty winds may still occur.
- PREPARE: Little to no preparations needed to protect
against tornadoes at this time. Keep informed of the latest
tornado situation.
- ACT: Listen for changes in the forecast.

- POTENTIAL IMPACTS: Little to None
- Little to no potential impacts from tornadoes.

* FOR MORE INFORMATION:
- sdcountyemergency.com
Updated: Oct 9, 8:22 PM Source: NWS Alert
Moderate Expected Likely

Tropical Cyclone Local Statement

Tropical Cyclone Local Statement issued October 9 at 2:08PM PDT by NWS San Diego CA
Oct 9, 2:08 PM → Oct 9, 10:15 PM
HLSSGX

This product covers EXTREME SOUTHWESTERN CALIFORNIA

**Tropical Storm Rachel Will Bring Coastal Flooding, Wind, and Rain
to Portions of Southern California Sunday**


NEW INFORMATION
---------------

* CHANGES TO WATCHES AND WARNINGS:
- None

* CURRENT WATCHES AND WARNINGS:
- A Tropical Storm Watch is in effect for San Diego County
Coastal Areas, San Diego County Deserts, San Diego County
Mountains, and San Diego County Valleys

* STORM INFORMATION:
- About 800 miles south-southwest of San Mateo Point CA or about
760 miles southwest of Mouth of Tijuana River CA
- 23.3N 124.0W
- Storm Intensity 45 mph
- Movement Northeast or 55 degrees at 7 mph

SITUATION OVERVIEW
------------------

Tropical Storm Rachel is currently 800 miles southwest of San Diego,
moving northeast towards Northern Baja. Rachel is expected to make
landfall somewhere near the US/Mexico Border late Saturday night.
Tropical storm level impacts have the potential to reach San Diego
County. A Tropical Storm Watch is in effect for all of San Diego
County. The main concerns with Tropical Storm Rachel are coastal
flooding, wind, and periods of heavy rain. The majority of impacts from
the tropical storm are expected on Sunday.

South swell from Tropical Storm Rachel will arrive on Sunday. The
combination of the swell, increased onshore winds, and high tides over
7 feet will maintain a threat of coastal flooding and beach erosion
along beaches in San Diego County. Surf on Sunday is currently
expected to be 6 to 9 feet, decreasing to 3 to 6 feet for Monday and
Tuesday. Confidence in impactful coastal flooding is high, with
significant coastal flooding and beach erosion increasingly possible.

Widespread rain is expected on Sunday from Tropical Storm Rachel.
There is expected to be a gradient in rainfall amounts with the higher
amounts on the southeastern side of the storm. We have the highest
confidence that the heaviest rain will occur over San Diego county
mountains and deserts. Peak rainfall rates of 0.50 to 0.60 inches are
possible for the coast and valleys, 0.50 to 0.70 inches per hour
possible for the deserts, and 0.70 to 1 inch per hour for the
mountains. Current forecast has rainfall totals of 0.50 to 1.25 inches
for the coast, valleys, and deserts and 1 to 2 inches for the
mountains. Areas of flash and urban flooding are possible, especially
where the maximum rainfall rates occur. The San Diego River at Fashion
Valley is currently forecast to peak at 7.4 feet (which is just below
monitor stage) Sunday afternoon. Those with interests near the San
Diego River should continue to monitor.

Increased winds are expected with the onset and passage of Tropical
Storm Rachel. Sustained winds of 39+ mph are expected on the southeast
side of the storm. Based on the current track, more southern and
eastern parts of the county are most likely to see winds of this
magnitude. Regardless, strong sustained winds and wind gusts can be
expected on Sunday. Winds may be enhanced by local terrain with gusts
40 to 55 mph on the desert slopes of the mountains and into the
deserts. Local gusts up to 60 mph possible on mountain ridges.

POTENTIAL IMPACTS
-----------------

* WIND:
Prepare for hazardous wind having possible limited impacts across
EXTREME SOUTHWESTERN CALIFORNIA. Potential impacts include:
- Damage to porches, awnings, carports, sheds, and unanchored
mobile homes. Unsecured lightweight objects blown about.
- Many large tree limbs broken off. A few trees snapped or
uprooted, but with greater numbers in places where trees are
shallow rooted, especially in coastal and valley locations that
don't typically experience strong winds. Some fences and
roadway signs blown over.
- A few roads impassable from debris, particularly within urban
or heavily wooded places. Hazardous driving conditions on
bridges and other elevated roadways.
- Scattered power and communications outages.

* FLOODING RAIN:
Prepare for life-threatening rainfall flooding having possible
extensive impacts across San Diego County. Potential impacts include:
- Major rainfall flooding may prompt many evacuations and rescues.
- Rivers and tributaries may rapidly overflow their banks in
multiple places. Small streams, creeks, canals, arroyos, and
ditches may become dangerous rivers. In mountain areas,
destructive runoff may run quickly down valleys while
increasing susceptibility to rockslides and mudslides. Flood
control systems and barriers may become stressed.
- Flood waters can enter many structures within multiple
communities, some structures becoming uninhabitable or washed
away. Many places where flood waters may cover escape routes.
Streets and parking lots become rivers of moving water with
underpasses submerged. Driving conditions become dangerous.
Many road and bridge closures with some weakened or washed out.

Prepare for dangerous rainfall flooding having possible significant
impacts across San Diego County.

* OTHER COASTAL HAZARDS:
High tides over 7 ft, combined with high surf and gusty onshore winds
will increase the threat for coastal flooding across area beaches.
Additionally surf of 6 to 9 ft will create dangerous swimming
conditions. There is increasing potential for significant coastal
flooding and beach erosion.

PRECAUTIONARY/PREPAREDNESS ACTIONS
----------------------------------

* EVACUATIONS:
Follow the advice of local officials.

* OTHER PREPAREDNESS INFORMATION:
If you live in a place particularly vulnerable to flooding, such as
near the ocean, in a low-lying or poor drainage area, or in a valley,
plan to move to safe shelter on higher ground.

Now is the time to check your emergency plan and emergency supplies
kit and take necessary actions to protect your family and secure your
home or business.

Always heed the advice of local officials and comply with orders that
are issued.

Closely monitor weather.gov, NOAA Weather Radio and local news
outlets for official storm information. Listen for possible changes
to the forecast.

* ADDITIONAL SOURCES OF INFORMATION:
- For information on appropriate preparations see ready.gov
- For information on creating an emergency plan see getagameplan.org
- For additional disaster preparedness information see redcross.org

NEXT UPDATE
-----------

The next local statement will be issued by the National Weather
Service in San Diego CA around 8 PM PDT, or sooner if conditions
warrant.
Updated: Oct 9, 8:22 PM Source: NWS Alert