Arcata 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 Arcata.

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

Heat Advisory issued August 7 at 2:32PM PDT until August 9 at 8:00PM PDT by NWS Hanford CA

* WHAT...High temperatures up to 109 degrees and multiple days of Major Heat Risk. * WHERE...San Joaquin Valley and adjacent foothills, Lake Isabella, and the Kern River Valley. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...Hot temperatures and limited overnight relief may cause heat illnesses. * ADDITIONAL DETAILS...Afternoon high temperatures of 105 to 109 degrees will occur daily through the upcoming weekend. Overnight lows will generally only fall into the mid 60s to mid 70s with little overnight relief.

Heat Advisory issued August 7 at 2:32PM PDT until August 9 at 8:00PM PDT by NWS Hanford CA

* WHAT...High temperatures up to 108 degrees and multiple days of Major Heat Risk. * WHERE...West Side Mountains north of 198. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events, especially those with little overnight relief from the heat. * ADDITIONAL DETAILS...Afternoon high temperatures of 105 to 108 degrees will occur daily through the upcoming weekend. Overnight lows will generally only fall into the mid 60s to mid 70s with little overnight relief.

Extreme Heat Warning issued August 7 at 2:32PM PDT until August 9 at 8:00PM PDT by NWS Hanford CA

* WHAT...Dangerously hot conditions with multiple days of Major to Extreme Heat Risk. * WHERE...Indian Wells Valley, Mojave Desert, and Mojave Desert Slopes. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events, especially those with little overnight relief from the heat. * ADDITIONAL DETAILS...Dangerously hot conditions with high temperatures up to 112 degrees. Overnight lows will range from 75-80 degrees.

Heat Advisory issued August 7 at 2:15PM PDT until August 9 at 8:00PM PDT by NWS Las Vegas NV

* WHAT...Hot conditions expected with highs 80 to 90 degrees above 8000 feet and 90 to 100 degrees below 8000 feet. This will result in Moderate Heat Risk. * WHERE...In California, Eastern Sierra Slopes and White Mountains of Inyo County. In Nevada, Sheep Range and Spring Mountains-Red Rock Canyon. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses.

Extreme Heat Warning issued August 7 at 2:15PM PDT until August 9 at 8:00PM PDT by NWS Las Vegas NV

* WHAT...Dangerously hot conditions with highs 110 to 120 degrees across the Mojave Desert. Highs 95 to 105 degrees across most of the southern Great Basin and Arizona Strip. Little to no overnight relief is expected, particularly in the Mojave Desert where lows of 80 to 95 degrees are forecast. This will result in Major-to-Extreme Heat Risk. * WHERE...Portions of northwest Arizona, southeast California, and south central and southern Nevada. * WHEN...Until 8 PM PDT /8 PM MST/ Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events.

Extreme Heat Warning issued August 7 at 12:12PM MST until August 9 at 8:00PM MST by NWS Phoenix AZ

* WHAT...Dangerously hot and humid conditions. Afternoon temperatures 108 to 117 degrees. Major Heat Risk. * WHERE...Imperial County, including the Imperial Valley and El Centro. * WHEN...Until 8 PM PDT Sunday. * 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 August 7 at 12:12PM MST until August 9 at 8:00PM MST by NWS Phoenix AZ

* WHAT...Dangerously hot and humid conditions. Afternoon temperatures 98 to 110 degrees. Major Heat Risk. * WHERE...Chuckwalla Mountains, Chiriaco Summit, and Joshua Tree National Park. * WHEN...Until 8 PM PDT Sunday. * 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 August 7 at 12:12PM MST until August 9 at 8:00PM MST by NWS Phoenix AZ

* WHAT...Dangerously hot and humid conditions. Afternoon temperatures 107 to 115 degrees. Major Heat Risk. * WHERE...In Arizona, La Paz and Yuma counties. In California, Palo Verde Valley. * WHEN...Until 8 PM MST /8 PM PDT/ Sunday. * 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.

Heat Advisory issued August 7 at 11:38AM PDT until August 9 at 10:00PM PDT by NWS Sacramento CA

* WHAT...High temperatures of 102 to 108 and low temperatures of 65 to 80 expected, with Moderate to Major HeatRisk. * WHERE...The Sacramento and San Joaquin Valleys, foothills, Coast Range, and Sierra from Highway 50 northward * WHEN...Until 10 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses, especially anyone without effective cooling and/or adequate hydration. * ADDITIONAL DETAILS...The heat is expected to peak on Saturday, with areas of Major HeatRisk. Hottest temperatures and warmest overnight lows expected in the northern Sacramento Valley and Sierra foothills thermal belts.

Heat Advisory issued August 7 at 10:06AM PDT until August 9 at 10:00PM PDT by NWS San Francisco CA

* WHAT...Daytime highs in the mid 90s to low 100s. Nighttime lows in the mid 60s to low 80s (especially in the higher elevations). * WHERE...Southern Salinas Valley/Arroyo Seco and Lake San Antonio County. * WHEN...From 10 AM Saturday to 10 PM PDT Sunday. * 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.

Heat Advisory issued August 7 at 10:06AM PDT until August 9 at 10:00PM PDT by NWS San Francisco CA

* WHAT...Daytime highs in the mid 90s to low 100s. Nighttime lows in the mid 60s to low 80s (especially in the higher elevations). * WHERE...The Santa Clara Valley and Eastern Hills, The East Bay Hills and Valleys, Western Sonoma County Hills, The Santa Cruz Mountains, Interior Monterey County and the Santa Lucia Range, Most of San Benito County and the Cholame Hills in Southeast Monterey County, and North Bay Interior Mountains. * WHEN...From 10 AM Saturday to 10 PM PDT Sunday. * 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.

Heat Advisory issued August 7 at 10:03AM PDT until August 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...High temperatures mostly in the mid 80s to upper 90s below 6500 feet expected. * WHERE...San Bernardino County Mountains. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses.

Extreme Heat Warning issued August 7 at 10:03AM PDT until August 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...Dangerously hot conditions with temperatures of 100 to 110 expected. * WHERE...Apple and Lucerne Valleys. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events.

Heat Advisory issued August 7 at 10:03AM PDT until August 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...High temperatures mostly in the mid 80s to upper 90s expected. * WHERE...San Diego County Mountains. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses.

Heat Advisory issued August 7 at 10:03AM PDT until August 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...High temperatures in the mid 90s to 103 expected. * WHERE...San Bernardino and Riverside County Valleys-The Inland Empire. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses.

Heat Advisory issued August 7 at 10:03AM PDT until August 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...High temperatures in the mid to upper 90s, locally up to 100 degrees east of Interstate 15. * WHERE...San Diego County Valleys. * WHEN...From 10 AM Saturday to 8 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses.

Extreme Heat Warning issued August 7 at 10:03AM PDT until August 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...Dangerously hot conditions with high temperatures of 108 to 114 expected. * WHERE...Coachella Valley, San Diego County Deserts, and San Gorgonio Pass near Banning. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...Heat related illnesses increase significantly during extreme heat events.

Heat Advisory issued August 7 at 10:03AM PDT until August 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...High temperatures mostly in the mid 80s to upper 90s below 6500 feet expected. * WHERE...Riverside County Mountains. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses.

Heat Advisory issued August 7 at 10:03AM PDT until August 9 at 8:00PM PDT by NWS San Diego CA

* WHAT...High temperatures in the low 90s east of Interstate 5. High temperatures in the mid-90s in the Santa Ana mountains. * WHERE...Orange County Inland Areas and Santa Ana Mountains and Foothills. * WHEN...From 10 AM Saturday to 8 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses.

Heat Advisory issued August 7 at 10:02AM PDT until August 8 at 11:00PM PDT by NWS Medford OR

* WHAT...Hot temperatures of 95 to 105 degrees are expected, possibly up to 110 degrees in the lower Klamath River Valley, with low temperatures in the 50s to near 60 degrees. Lows of 60 to 65 degrees over higher terrain. * WHERE...Central Siskiyou County, Modoc County, North Central and Southeast Siskiyou County, Northeast Siskiyou and Northwest Modoc Counties, and Western Siskiyou County. This includes the lower Klamath River Valley, the Shasta Valley, Weed, Montague, Alturas, Tionesta, Tennant, Macdoel and Tulelake. * WHEN...Until 11 PM PDT Saturday. * IMPACTS...Hot temperatures will lead to a moderate risk of heat illnesses, especially for those without adequate cooling methods.

Heat Advisory issued August 7 at 10:02AM PDT until August 8 at 11:00PM PDT by NWS Medford OR

* WHAT...Hot afternoon temperatures of 95 to 100 degrees are expected, with low temperatures in the low to mid 50s. * WHERE...South Central Siskiyou County, including Mount Shasta City. * WHEN...Until 11 PM PDT Saturday. * IMPACTS...Hot temperatures will lead to a moderate risk of heat illnesses, especially for those without adequate cooling methods.

Heat Advisory issued August 7 at 9:11AM PDT until August 9 at 8:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Very warm temperatures of 90 to 105 degrees expected. * WHERE...Eastern San Gabriel Mountains, Interstate 5 Corridor, San Luis Obispo County Interior Valleys, San Luis Obispo County Mountains, Santa Barbara County Interior Mountains, Santa Susana Mountains, Southern Ventura County Mountains, and Western San Gabriel Mountains and Highway 14 Corridor. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses.

Extreme Heat Warning issued August 7 at 9:11AM PDT until August 9 at 8:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Dangerously hot conditions with temperatures 102 to 110. * WHERE...Antelope Valley and nearby foothills. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...There is a high risk for dangerous heat illness, especially for sensitive groups like the very young, the very old, those without air conditioning, and those active outdoors.

Heat Advisory issued August 7 at 9:11AM PDT until August 9 at 8:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Very warm temperatures of 90 to 100 degrees expected. * WHERE...A portion of southwest California. * WHEN...From 10 AM Saturday to 8 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses.

Extreme Heat Warning issued August 7 at 9:11AM PDT until August 9 at 8:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Dangerously hot daytime conditions with high temperatures between 95 and 105 common, except locally up to 108 in the hottest locations. * WHERE...Northern Ventura County Mountains. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...There is a high risk for dangerous heat illness, especially for sensitive groups like the very young, the very old, those without air conditioning, and those active outdoors.

Extreme Heat Warning issued August 7 at 9:11AM PDT until August 9 at 8:00PM PDT by NWS Los Angeles/Oxnard CA

* WHAT...Hot daytime conditions with high temperatures between 98 and 106 common. * WHERE...The Cuyama Valley. * WHEN...Until 8 PM PDT Sunday. * IMPACTS...There is a high risk for dangerous heat illness, especially for sensitive groups like the very young, the very old, those without air conditioning, and those active outdoors.

Heat Advisory issued August 7 at 8:47AM PDT until August 10 at 8:00AM PDT by NWS Reno NV

* WHAT...High temperatures of 97 to 102 degrees with overnight lows of 55 to 70 degrees. Widespread Moderate to Major HeatRisk. * WHERE...In California, Lassen-Eastern Plumas-Eastern Sierra Counties and Surprise Valley California. In Nevada, Northern Washoe County and Greater Reno-Carson City-Minden Area. * WHEN...Until 8 AM PDT Monday. * IMPACTS...Heat related illnesses will be more likely, especially for those spending extended periods outdoors, in poorly cooled indoor spaces, or who are sensitive to heat.

Heat Advisory issued August 7 at 6:31AM PDT until August 9 at 10:00PM PDT by NWS Eureka CA

* WHAT...Temperatures of 100 to 110 will produce moderate to major HeatRisk. * WHERE...Trinity County. * WHEN...Until 10 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses. * ADDITIONAL DETAILS...Hot temperatures are expected to continue into the weekend. Saturday will be the peak day for HeatRisk!

Heat Advisory issued August 7 at 6:31AM PDT until August 9 at 10:00PM PDT by NWS Eureka CA

* WHAT...Temperatures of 90 to 101 will produce moderate HeatRisk. * WHERE...Southwestern Interior Mendocino. * WHEN...From 10 AM Saturday to 10 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses. * ADDITIONAL DETAILS...Hot temperatures are expected to continue into the weekend. Saturday will be the peak day for HeatRisk!

Heat Advisory issued August 7 at 6:31AM PDT until August 9 at 10:00PM PDT by NWS Eureka CA

* WHAT...Temperatures of 100 to 110 will produce moderate to major HeatRisk. * WHERE...Northern Mendocino Interior, Lake County, and Southeastern Interior Mendocino. * WHEN...From 11 AM this morning to 10 PM PDT Sunday. * IMPACTS...Hot temperatures may cause heat illnesses.

Coastal Flood Advisory issued August 6 at 7:45PM PDT until August 13 at 2:00AM PDT by NWS San Francisco CA

* WHAT...Up to 1.7 ft of inundation above ground level is possible in low-lying areas near shorelines and tidal waterways. * WHERE...Bayshore locations along the San Francisco Bay, San Pablo Bay, and Monterey Bay. * WHEN...From 5 PM Friday to 2 AM PDT Thursday. * IMPACTS...Flooding of lots, parks, and roads with only isolated road closures expected. * ADDITIONAL DETAILS...At the San Francisco tidal gauge, high tide is expected to be 1.0 ft above normal (6.84 ft MLLW) at 6:55 PM Friday 8/7, 1.3 ft above normal (7.15 ft MLLW) at 8:00 PM Saturday 8/8, 1.6 ft above normal (7.44 ft MLLW) at 9:02 PM Sunday 8/9, 1.7 ft above normal (7.56 ft MLLW) at 10:01 PM Monday 8/10, 1.6 ft above normal (7.44 ft MLLW) at 10:57 PM Tuesday 8/11, and 1.3 ft above normal (7.14 ft MLLW) at 11:49 PM Wednesday 8/12. These predictions include both astronomical tides and roughly 3-6 inches of additional water mainly from a combination of thermal expansion and accumulated sea level rise since the tidal datum was established (1983-2001). High tide varies up to 90 minutes earlier or later along the Pacific Coast and through the San Francisco Bay, respectively.