San Martin Warnings, Watches and Advisories

When a severe thunderstorm warning is issued, the storm may produce damaging winds, large hail, dangerous lightning, and heavy rain. In some cases, heavy rainfall produced by a severe storm can also lead to flash flooding. Do not drive vehicles through flooded areas. The water depth or fast flowing water/mud/debris from a flash flood will make road conditions unsafe. Do not rely soley on data presented here or other third-party websites - always check your official national and local weather service agency website, socials, radio and/or TV stations for making critical decisions related to weather events.

Please carefully read each posted Warning and Alert as it relates to the area(s) being affected. We may provide a wider range of issued severe weather warnings for surrounding cities and counties, so some alerts may not directly impact this location. This is done to help with preparing for severe weather that may overlap or be heading towards San Martin.

Use the Radar Maps link provided to understand the trajectory of a storm.

Heat Advisory issued September 8 at 3:44AM PDT until September 10 at 8:00PM PDT by NWS San Diego CA

* WHAT...For the Extreme Heat Warning, dangerously hot conditions with high temperatures in the mid 80s at the beaches to 90s for higher coastal terrain with low temperatures in the lower to mid 70s. For the Heat Advisory, high temperatures around 80 near the coast to the lower to mid 90s for higher coastal terrain. * WHERE...Orange County Coastal Areas and San Diego County Coastal Areas. * WHEN...For the Extreme Heat Warning, until 8 PM PDT Wednesday. For the Heat Advisory, from 8 PM Wednesday to 8 PM PDT Thursday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events. Hot temperatures may cause heat illnesses. * ADDITIONAL DETAILS...Major to Extreme HeatRisk through Wednesday. Warm overnight low temperature will limit relief from the heat.

Extreme Heat Warning issued September 8 at 3:44AM PDT until September 11 at 8:00PM PDT by NWS San Diego CA

* WHAT...Dangerously hot conditions with high temperatures of 106 to 110 expected with low temperatures in the 80s expected. * WHERE...Coachella Valley, San Diego County Deserts, and San Gorgonio Pass near Banning. * WHEN...From 10 AM Wednesday to 8 PM PDT Friday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events. * ADDITIONAL DETAILS...Areas of Major HeatRisk. Very warm overnight temperatures will limit relief from the heat.

Heat Advisory issued September 8 at 3:44AM PDT until September 10 at 8:00PM PDT by NWS San Diego CA

* WHAT...High temperatures in the 90s below 5500 feet expected. * WHERE...Riverside County Mountains and San Diego County Mountains. * WHEN...From 10 AM this morning to 8 PM PDT Thursday. * IMPACTS...Hot temperatures may cause heat illnesses. * ADDITIONAL DETAILS...Moderate HeatRisk. Warm overnight temperatures will limit relief from the heat.

Heat Advisory issued September 8 at 3:44AM PDT until September 10 at 8:00PM PDT by NWS San Diego CA

* WHAT...For the Extreme Heat Warning, dangerously hot conditions with temperatures high temperatures in the upper 90s to 108 with low temperatures in the 70s expected. For the Heat Advisory, high temperatures in the mid 90s to 102 expected. * WHERE...San Bernardino and Riverside County Valleys-The Inland Empire. * WHEN...For the Extreme Heat Warning, until 8 PM PDT Wednesday. For the Heat Advisory, from 8 PM Wednesday to 8 PM PDT Thursday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events. Hot temperatures may cause heat illnesses. * ADDITIONAL DETAILS...Major HeatRisk through Wednesday. Warm overnight temperatures will limit overnight relief from the heat.

Heat Advisory issued September 8 at 3:44AM PDT until September 10 at 8:00PM PDT by NWS San Diego CA

* WHAT...For the Extreme Heat Warning, dangerously hot conditions with high temperatures in the 90s with low temperatures in the 70s expected. For the Heat Advisory, high temperatures in the upper 80s to mid 90s expected. * WHERE...Orange County Inland Areas. * WHEN...For the Extreme Heat Warning, until 8 PM PDT Wednesday. For the Heat Advisory, from 8 PM Wednesday to 8 PM PDT Thursday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events.overnight * ADDITIONAL DETAILS...Major HeatRisk. Warm overnight temperatures will limit relief from the heat.

Heat Advisory issued September 8 at 3:44AM PDT until September 10 at 8:00PM PDT by NWS San Diego CA

* WHAT...For the Extreme Heat Warning, dangerously hot conditions with high temperatures in the mid 90s to 105 with low temperatures in the 70s expected. For the Heat Advisory, high temperatures in the 90s to 102 expected. * WHERE...San Diego County Valleys. * WHEN...For the Extreme Heat Warning, until 8 PM PDT Wednesday. For the Heat Advisory, from 8 PM Wednesday to 8 PM PDT Thursday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events. Hot temperatures may cause heat illnesses.

Extreme Heat Warning issued September 8 at 3:44AM PDT until September 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...For the Extreme Heat Warning, dangerously hot conditions with high temperatures in the mid 90s to 105 with low temperatures in the 70s expected. For the Heat Advisory, high temperatures in the 90s to 102 expected. * WHERE...San Diego County Valleys. * WHEN...For the Extreme Heat Warning, until 8 PM PDT Wednesday. For the Heat Advisory, from 8 PM Wednesday to 8 PM PDT Thursday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events. Hot temperatures may cause heat illnesses.

Extreme Heat Warning issued September 8 at 3:44AM PDT until September 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...For the Extreme Heat Warning, dangerously hot conditions with high temperatures in the 90s with low temperatures in the 70s expected. For the Heat Advisory, high temperatures in the upper 80s to mid 90s expected. * WHERE...Orange County Inland Areas. * WHEN...For the Extreme Heat Warning, until 8 PM PDT Wednesday. For the Heat Advisory, from 8 PM Wednesday to 8 PM PDT Thursday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events.overnight * ADDITIONAL DETAILS...Major HeatRisk. Warm overnight temperatures will limit relief from the heat.

Extreme Heat Warning issued September 8 at 3:44AM PDT until September 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...For the Extreme Heat Warning, dangerously hot conditions with temperatures high temperatures in the upper 90s to 108 with low temperatures in the 70s expected. For the Heat Advisory, high temperatures in the mid 90s to 102 expected. * WHERE...San Bernardino and Riverside County Valleys-The Inland Empire. * WHEN...For the Extreme Heat Warning, until 8 PM PDT Wednesday. For the Heat Advisory, from 8 PM Wednesday to 8 PM PDT Thursday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events. Hot temperatures may cause heat illnesses. * ADDITIONAL DETAILS...Major HeatRisk through Wednesday. Warm overnight temperatures will limit overnight relief from the heat.

Extreme Heat Warning issued September 8 at 3:44AM PDT until September 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...For the Extreme Heat Warning, dangerously hot conditions with high temperatures in the mid 80s at the beaches to 90s for higher coastal terrain with low temperatures in the lower to mid 70s. For the Heat Advisory, high temperatures around 80 near the coast to the lower to mid 90s for higher coastal terrain. * WHERE...Orange County Coastal Areas and San Diego County Coastal Areas. * WHEN...For the Extreme Heat Warning, until 8 PM PDT Wednesday. For the Heat Advisory, from 8 PM Wednesday to 8 PM PDT Thursday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events. Hot temperatures may cause heat illnesses. * ADDITIONAL DETAILS...Major to Extreme HeatRisk through Wednesday. Warm overnight low temperature will limit relief from the heat.

Heat Advisory issued September 8 at 2:52AM PDT until September 10 at 10:00PM PDT by NWS Hanford CA

* WHAT...High temperatures up to 102 and morning lows up to 75 expected. Widespread Moderate HeatRisk will be present with areas of Major HeatRisk in the foothills where the thermal belt is strongest and in urban areas. * WHERE...The San Joaquin Valley, Sierra Nevada Foothills, and West Side Hills along the Coastal Range. * WHEN...From 10 AM Wednesday to 10 PM PDT Thursday. * IMPACTS...Hot temperatures may cause heat illnesses, especially those without effective cooling and/or adequate hydration. * ADDITIONAL DETAILS...Little to no relief at night in areas of Major HeatRisk. Air conditioning is necessary; fans and open windows at night will not be enough.

High Surf Advisory issued September 8 at 2:29AM PDT until September 8 at 11:00PM PDT by NWS San Diego CA

* WHAT...Large breaking waves of 3 to 6 feet with sets up to 8 feet, highest at south and southwest-facing beaches. Strong and dangerous rip and longshore currents. Minor coastal flooding from a combination of high surf and high astronomical tides during the evenings. * WHERE...Beaches of Orange and San Diego Counties. * WHEN...Through 11 PM PDT today. * IMPACTS...Flooding of lots, parks, and roads with isolated road closures expected. Dangerous swimming and surfing conditions and beach erosion. * ADDITIONAL DETAILS...Predicted higher high tides: Newport Beach: 7.0 feet at 7:59 PM. La Jolla: 6.9 feet at 7:54 PM.

Coastal Flood Advisory issued September 8 at 2:29AM PDT until September 8 at 11:00PM PDT by NWS San Diego CA

* WHAT...Large breaking waves of 3 to 6 feet with sets up to 8 feet, highest at south and southwest-facing beaches. Strong and dangerous rip and longshore currents. Minor coastal flooding from a combination of high surf and high astronomical tides during the evenings. * WHERE...Beaches of Orange and San Diego Counties. * WHEN...Through 11 PM PDT today. * IMPACTS...Flooding of lots, parks, and roads with isolated road closures expected. Dangerous swimming and surfing conditions and beach erosion. * ADDITIONAL DETAILS...Predicted higher high tides: Newport Beach: 7.0 feet at 7:59 PM. La Jolla: 6.9 feet at 7:54 PM.

Heat Advisory issued September 8 at 2:10AM PDT until September 10 at 8:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Temperatures of 85 to 105 expected. 10 to 20 degrees above normal. * WHERE...Calabasas and Agoura Hills, Eastern San Fernando Valley, Eastern Santa Monica Mountains Recreational Area, Los Angeles County Beaches, Los Angeles County Inland Coast including Downtown Los Angeles, Los Angeles County San Gabriel Valley, Malibu Coast, Palos Verdes Hills, Western San Fernando Valley, and Western Santa Monica Mountains Recreational Area * WHEN...From 10 AM Wednesday to 8 PM PDT Thursday. * IMPACTS...Hot temperatures may cause heat illnesses. * ADDITIONAL DETAILS...Humid conditions will add to heat discomfort. Heat peaking on Wednesday for most areas, except likely peaking Thursday for the Santa Barbara South Coast. Chance for Heat Advisories to be extended into Friday.

Heat Advisory issued September 8 at 2:10AM PDT until September 10 at 8:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Temperatures between 85 and 105 expected. 10 to 15 degrees above normal. * WHERE...Calabasas and Agoura Hills, Eastern San Fernando Valley, Eastern Santa Monica Mountains Recreational Area, Los Angeles County Beaches, Los Angeles County Inland Coast including Downtown Los Angeles, Los Angeles County San Gabriel Valley, Malibu Coast, Palos Verdes Hills, Western San Fernando Valley, and Western Santa Monica Mountains Recreational Area * WHEN...From 10 AM this morning to 8 PM PDT Thursday. * IMPACTS...Hot temperatures may cause heat illnesses. * ADDITIONAL DETAILS...Humid conditions will add to heat discomfort. Heat peaking on Wednesday for most areas. Chance for Heat Advisories to be extended into Friday.

Extreme Heat Warning issued September 8 at 1:09AM MST until September 11 at 8:00PM MST by NWS Phoenix AZ

* WHAT...Dangerously hot conditions. Afternoon temperatures 106 to 112 expected. Major Heat Risk. * WHERE...Imperial County Southwest, Imperial County West, and Imperial Valley. * WHEN...From 10 AM this morning to 8 PM PDT Friday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events. Overexposure can cause heat cramps and heat exhaustion to develop and, without intervention, can lead to heat stroke.

Extreme Heat Warning issued September 8 at 1:09AM MST until September 11 at 8:00PM MST by NWS Phoenix AZ

* WHAT...Dangerously hot conditions. Afternoon temperatures 102 to 111 expected. Major Heat Risk. * WHERE...In Arizona, Central La Paz and Parker Valley. In California, Chuckwalla Valley and Palo Verde Valley. * WHEN...From 10 AM MST /10 AM PDT/ Wednesday to 8 PM MST /8 PM PDT/ Friday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events. Overexposure can cause heat cramps and heat exhaustion to develop and, without intervention, can lead to heat stroke.

Extreme Heat Warning issued September 8 at 12:09AM PDT until September 10 at 8:00PM PDT by NWS Las Vegas NV

* WHAT...Dangerously hot late-season conditions expected with high temperatures up to 112 to 116 in Death Valley and the Colorado River Valley; up to 105 to 110 in the Las Vegas Valley, Moapa Valley, and Pahrump Valley. * WHERE...Portions of northwest Arizona, southeast California, and southern Nevada. * WHEN...From 10 AM PDT / MST to 8 PM PDT / MST Thursday. * IMPACTS...Heat-related illnesses increase significantly during extreme heat.

Beach Hazards Statement issued September 7 at 7:12PM PDT until September 8 at 11:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Dangerous and potentially life threatening rip currents and breaking waves due to elevated surf expected. * WHERE...San Luis Obispo County Beaches, Santa Barbara County Central Coast Beaches, Santa Barbara County Southwestern Coast and Santa Barbara County Southeastern Coast. * WHEN...Through Tuesday evening. * IMPACTS...There is an increased risk of ocean drowning. Rip currents will be widespread and very strong, potentially pulling swimmers and surfers out to sea. Waves can wash people off beaches and rocks. Pooling of sea water is possible around high tide at beach areas that is uncommon with normal tidal ranges. Enhanced beach erosion is also possible. No significant damage is expected. * ADDITIONAL DETAILS...High tides will occur around 6.5 feet at 730pm today and 6.5 feet at 830pm on Tuesday.

Coastal Flood Advisory issued September 7 at 7:12PM PDT until September 8 at 11:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...For the Coastal Flood Advisory, moderate coastal flooding expected. For the High Surf Advisory, large breaking waves of 4 to 7 feet with local sets to 8 feet and dangerous and potentially life threatening rip currents. Highest waves on south- facing shores of Los Angeles County. * WHERE...Catalina and Santa Barbara Islands, Ventura County Beaches, Malibu Coast and Los Angeles County Beaches. * WHEN...Until 11 PM PDT Tuesday. * IMPACTS...There is an increased risk of ocean drowning. Rip currents will be widespread and very strong, potentially pulling swimmers and surfers out to sea. Large breaking waves can cause injury, wash people off beaches and rocks, and capsize small boats near shore. Significant beach erosion will occur. Flooding of sea water is likely, around the time of high tide, over vulnerable low-lying coastal areas such as parking lots, beaches, walkways, and low-lying roads. Of particular concern will be the Alamitos Peninsula area in Long Beach where coastal flooding will potentially cause local damage to structures near time of high tides. Other areas that will be susceptible to coastal flooding during the next couple of days include Catalina Island, and Oxnard to Malibu (including Point Mugu). * ADDITIONAL DETAILS...High tides occurred around 7 feet at 7 pm today and will be 7.2 feet at 8 pm on Tuesday.

High Surf Advisory issued September 7 at 7:12PM PDT until September 8 at 11:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...For the Coastal Flood Advisory, moderate coastal flooding expected. For the High Surf Advisory, large breaking waves of 4 to 7 feet with local sets to 8 feet and dangerous and potentially life threatening rip currents. Highest waves on south- facing shores of Los Angeles County. * WHERE...Catalina and Santa Barbara Islands, Ventura County Beaches, Malibu Coast and Los Angeles County Beaches. * WHEN...Until 11 PM PDT Tuesday. * IMPACTS...There is an increased risk of ocean drowning. Rip currents will be widespread and very strong, potentially pulling swimmers and surfers out to sea. Large breaking waves can cause injury, wash people off beaches and rocks, and capsize small boats near shore. Significant beach erosion will occur. Flooding of sea water is likely, around the time of high tide, over vulnerable low-lying coastal areas such as parking lots, beaches, walkways, and low-lying roads. Of particular concern will be the Alamitos Peninsula area in Long Beach where coastal flooding will potentially cause local damage to structures near time of high tides. Other areas that will be susceptible to coastal flooding during the next couple of days include Catalina Island, and Oxnard to Malibu (including Point Mugu). * ADDITIONAL DETAILS...High tides occurred around 7 feet at 7 pm today and will be 7.2 feet at 8 pm on Tuesday.

Frost Advisory issued September 7 at 11:06AM PDT until September 8 at 9:00AM PDT by NWS Medford OR

* WHAT...Widespread frost conditions, with local areas of sub-freezing temperatures as low as 31 degrees * WHERE...In California, valleys and basins in Modoc County. In Oregon, valleys and basins in Lake and Klamath counties. This includes the communities of Crescent, Chemult, Fort Rock and the rest of the Christmas Valley, Chiloquin, Sprague River, Bly, cities in the Klamath Basin, areas east of Lakeview, Canby, and Alturas. * WHEN...From 3 AM to 9 AM PDT Tuesday. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered. Animals not acclimated to these conditions may be harmed if left outside for extended periods.

Heat Advisory issued September 7 at 10:30AM PDT until September 10 at 10:00PM PDT by NWS Sacramento CA

* WHAT...High temperatures 97 to 102 and low temperatures 65 to 75 expected, with widespread Moderate HeatRisk and areas of Major HeatRisk. * WHERE...The central and southern Sacramento Valley, northern San Joaquin Valley, Delta and Carquinez Strait, Foothills, and portions of the Coast Range. * WHEN...From 10 AM Wednesday to 10 PM PDT Thursday. * IMPACTS...Hot temperatures may cause heat illnesses, especially to anyone without effective cooling and/or adequate hydration. * ADDITIONAL DETAILS...Hottest temperatures and areas of Major HeatRisk are expected to occur on Thursday. Warmest overnight lows are expected in the Sierra foothills thermal belts.

Heat Advisory issued September 7 at 10:27AM PDT until September 10 at 10:00PM PDT by NWS San Francisco CA

* WHAT...Hot conditions with temperatures 10 to 20 degrees above normal. * WHERE...Bay Area and Central Coast. * WHEN...From 10 AM Wednesday to 10 PM PDT Thursday. * IMPACTS...This level of heat affects most individuals sensitive to heat, especially those without effective cooling and/or adequate hydration. Impacts possible in some health systems and in heat-sensitive industries. Hot conditions can cause heat illnesses.