An Extraordinary March Heat Emergency
This is not a normal spring weekend in Los Angeles. What is happening outside right now is something meteorologists are describing in terms they rarely use for March, and the National Weather Service is not hedging its language. As of midnight tonight, the advisory footprint has expanded again.
The National Weather Service has issued a High Risk for Heat Illness advisory describing current conditions as "extremely rare heat for March," urging residents to adjust plans and limit strenuous outdoor activities to just the early morning hours.
Dangerously hot conditions with temperatures between 96 and 104 degrees are expected across Los Angeles County, with warm overnight low temperatures contributing to the heat risk, especially in mountain and foothill locations.
Temperatures are running 25 to 35 degrees above normal, and many daily records will be shattered. For context, the average high temperature in Los Angeles on March 20 is 68 degrees Fahrenheit. The forecasts running through this weekend are projecting conditions that belong to late August, not the first day of spring.
The Extreme Heat Warning covers the Los Angeles Inland Coast including Downtown LA, the Western and Eastern Santa Monica Mountains, Calabasas and Agoura Hills, the West and East San Fernando Valley, the Santa Susana Mountains, the Western and Eastern San Gabriel Mountains, and the San Gabriel Valley. A separate Heat Advisory covers the Malibu Coast, Los Angeles County Beaches, Palos Verdes Hills, and Catalina and Santa Barbara Islands, running through Saturday.
That advisory footprint covers virtually every trail in Los Angeles County. There is nowhere in this region where a midday hike this weekend is a good idea. But there are places where an early morning or coastal hike can still be done safely, and that is what this guide is for.
"Heat causes more deaths in the U.S. annually than floods, storms, and lightning combined."
— Muntu Davis, MD, MPH, Los Angeles County Health Officer
Read that twice. More deaths than floods, storms, and lightning combined. This is a genuine public health emergency, not a weather inconvenience.
Timing is Everything
Before any trail recommendation, before any gear list, before anything else, the timing of your outdoor activity this weekend is the most consequential decision you will make.
Try to limit strenuous activities to early morning or evening. The NWS specifically issued guidance recommending that outdoor exertion be confined to these windows to reduce heat illness risk.
Schedule strenuous outdoor tasks for the early morning or late evening.
What does early morning actually mean in practice for a Los Angeles hike this weekend? It means starting your hike no later than 7 a.m. and being back at your car no later than 9:30 a.m. That window, from just after dawn until about two hours after sunrise, is when temperatures are at their daily minimum and the sun is still at a low angle. After 10 a.m. this weekend, exposed trails in the Santa Monica Mountains, Griffith Park, and the San Gabriel Mountains will be rapidly approaching conditions where heat exhaustion becomes a real risk for healthy adults moving at a normal pace.
The overnight lows this week have been warm rather than cool, which is the meteorological detail that compounds the danger. Normally, nighttime temperatures allow the ground, the rocks, and the air to cool significantly before the next day's heat arrives. This week, the overnight temperatures have stayed elevated, meaning the trails you step onto at 7 a.m. Saturday are already carrying accumulated heat from the previous day. That residual warmth, combined with rapid morning heating, compresses the safe activity window even further than it would be on a typical hot day.
Best Shaded Trails Before 9 a.m.
If you are committed to getting outdoors this weekend, the following trails offer the best combination of shade, accessibility, and shorter distances that allow you to start and finish before the dangerous midday heat arrives.
Ferndell Nature Trail, Griffith Park
Ferndell is one of the most reliably shaded short walks in Los Angeles and the best option for families with young children who want outdoor time this weekend. The trail runs through a fern-lined canyon with consistent tree canopy cover, and the flat, paved path means you are moving efficiently rather than working against elevation.
The key is the timing. The parking area off Ferndell Drive near the Los Angeles Zoo is accessible early, and being inside the canyon by 6:30 a.m. puts you in the best shade available in Griffith Park before the temperature climbs. The trail is roughly 1.5 miles round trip, meaning a comfortable pace gets you back before 8 a.m. Do not extend the hike into the more exposed Griffith Park trails beyond the canyon this weekend.
The playground at the end of Ferndell near The Trails Café is in open sun. Keep children out of that area this weekend after 9 a.m.
Eaton Canyon Falls Trail, Pasadena
Eaton Canyon in Pasadena offers significant riparian shade in its lower sections, where the trail follows the creek bed before climbing toward the falls. The lower canyon section, roughly the first mile and a half from the parking area, has meaningful tree cover from cottonwoods, willows, and native shrubs that creates a cooler microclimate than fully exposed mountain trails.
Start no later than 6 a.m. to reach the falls and return before 9 a.m. The falls are a 3.2-mile round trip, and the pace required to complete that in three hours is brisk enough to generate significant body heat. Bring twice the water you think you need. The canyon can feel misleadingly cool in the early morning shade, and the temperature on the return climb in direct sunlight will be significantly higher than what you experienced walking in.
Do not go past the falls. The exposed ridgeline above the canyon is completely unshaded and will be genuinely dangerous by mid-morning.
Malibu Creek State Park: The MAS*H Site Trail
The lower section of the main trail at Malibu Creek State Park follows the creek and offers scattered riparian shade that makes it more tolerable in the early morning than fully exposed inland trails. The MAS*H site is 3.8 miles round trip and gets direct sun for significant portions of the route, so the timing window is even tighter here than at Ferndell or Eaton Canyon. Start by 6 a.m. and turn back if you are not at the site by 7:30 a.m.
Malibu Creek also benefits from the adjacent coastal influence. The Heat Advisory rather than the more severe Extreme Heat Warning covers the Malibu Coast, which means temperatures at the park should run slightly lower than the 96 to 104 degree range affecting inland areas. "Slightly lower" in this context still means potentially 88 to 92 degrees by 10 a.m., so the early start remains essential.
Coastal Options: Beach Advisory Advantage
The Malibu Coast, Los Angeles County Beaches, and Palos Verdes are under a Heat Advisory rather than an Extreme Heat Warning, which reflects the moderating influence of ocean breezes on coastal temperatures. That distinction makes coastal areas the most viable outdoor option for Angelenos this weekend who do not want to set an alarm for 5:30 a.m. to beat the heat.
The Strand at Santa Monica and Venice
The Marvin Braude Trail along the beach, from Santa Monica to Venice and beyond, gets consistent ocean breezes that will make conditions considerably more tolerable than any inland location. Officials noted that high risks exist for heat-related illness particularly for workers and residents in coastal areas lacking air conditioning, but coastal areas with ocean exposure will run meaningfully cooler than inland locations this weekend.
The beach is also the most appropriate outdoor destination for families with young children this weekend. Water is immediately accessible for cooling. The flat surface reduces exertion. Shade canopies and covered picnic areas are available near the Santa Monica Pier. And the walk from the pier toward Venice can be done at any pace, including a leisurely stroll that keeps the body temperature in a safe range.
Bring sunscreen with SPF 30 or higher. The combination of high temperatures and strong spring UV is more intense than it appears, and heat-related illness at the beach tends to be underestimated because the ocean breeze creates a misleading sense of coolness.
Palos Verdes Bluff Trail
The Bluff Trail along the Palos Verdes Peninsula runs between Portuguese Bend Reserve and the Point Vicente Lighthouse, with consistent ocean views and sea breezes that keep the temperature several degrees below inland readings throughout the day. The trail is partially shaded by coastal scrub and offers bench seating for rest breaks.
The 2.8-mile round trip along the main bluff section is manageable in the morning hours without the time pressure of inland trails. Start before 9 a.m. and you will be working in conditions that are difficult but not dangerous for healthy adults who are properly hydrated. Carry a minimum of two liters of water per person.
Trails to Avoid This Weekend
Some of the most popular hikes in Los Angeles should be considered off-limits until the heat breaks.
- The Runyon Canyon Loop: Fully exposed, no shade, popular enough that the crowd density itself adds to the ambient heat. Do not attempt after 7 a.m.
- Mount Wilson via Chantry Flat: The full elevation gain on this trail under these temperatures creates a sustained cardiac and thermal load that is genuinely dangerous. Skip it this weekend entirely.
- The Hollywood Sign Trail from Beachwood Drive: The exposed ridgeline trail to the Hollywood Sign has minimal shade and moderate elevation gain. On a normal day it is a demanding hike. This weekend it is a medical risk. The views are not worth it.
- Any exposed San Gabriel Mountains summit trail: The San Gabriel Mountains are under the Extreme Heat Warning. Warm overnight low temperatures will contribute to the heat risk especially in the mountain and foothill locations. Elevation does moderate temperatures, but not enough on a day forecast to hit 96 to 104 degrees at lower elevations.
- Griffith Park summit trails after 8 a.m.: The exposed western slopes of Griffith Park that lead toward the Observatory from the north should be avoided during the heat of the day. The Observatory itself, reached by car or the LADOT shuttle from Vermont and Sunset, is a better option than hiking to it this weekend.
Essential Gear for This Weekend
The minimum for any outdoor activity this weekend is not optional. These are the items that prevent a difficult situation from becoming a medical emergency.
- Water: Drinking plenty of water frequently is vital for those exposed to heat. An individual may produce as much as 2 to 3 gallons of sweat per day. To replenish that fluid, you should drink 3 to 4 cups of water every hour. For a two-hour morning hike in these conditions, carry a minimum of two liters. For families with children, add a full liter per child beyond what you think is necessary.
- Electrolytes: Water alone does not replace what you lose in sweat. Sodium and potassium losses compound heat exhaustion. Sports drinks, electrolyte tablets, or salted snacks address this. Bring both.
- A hat with a full brim: A baseball cap protects your face. A full-brim hat protects your face, ears, and the back of your neck, which is where sun exposure accumulates most dangerously on exposed trails. This weekend is a full-brim weekend.
- Sunscreen: Apply SPF 30 or higher before you leave the house. Reapply if you are out for more than 90 minutes.
- A way to check the time: It sounds obvious, and it is, but trail starts in the early morning euphoria of a cool canyon can stretch without people noticing. Know what time you need to turn back and hold that deadline.
Recognizing Heat Illness
If you or someone around you experiences symptoms of heat stroke or heat exhaustion, such as dizziness, nausea, rapid heartbeat, confusion, or passing out, seek medical help immediately.
The distinction between heat exhaustion and heat stroke is the difference between a serious situation and a life-threatening emergency. Heat exhaustion presents as heavy sweating, weakness, cold or pale and clammy skin, weak pulse, nausea, and possible fainting. The treatment is to move the person to shade, loosen clothing, apply cool wet cloths, and give sips of water.
Heat stroke is the emergency. Symptoms include a high body temperature above 103 degrees, hot and red skin that is dry or damp, rapid and strong pulse, and possible unconsciousness. Call 911 immediately. Do not attempt to manage heat stroke on a trail without professional medical assistance.
If anyone in your group shows signs of either condition before you have finished your hike, turn back immediately. No view, no summit, no trail completion is worth the consequences of ignoring early warning signs in these temperatures.
The Weekend Forecast
Saturday brings a temporary 5 to 10-degree cooling trend for coastal and valley areas. Sunday temperatures begin climbing again into the 80s and low 90s. The following Monday through Thursday, significant warming resumes, with excessive heat possible by midweek.
Saturday's slight moderation is real but limited. A 5 to 10-degree drop from Friday's peak of 96 to 104 degrees still puts Saturday in the high 80s to low 90s range across much of the county. The early start rule still applies on Saturday. The coastal option remains your most comfortable outdoor environment.
Sunday begins a new warming trend that suggests the second half of spring break week will not be significantly easier than this weekend for outdoor plans. If you are planning outdoor activities for children during the school holiday, the early morning and beach structure from this weekend should carry forward into next week.
Cooling Centers Across Los Angeles County
For Angelenos without air conditioning at home, cooling centers are the most important immediate resource this weekend. For information about cooling centers operated by Los Angeles County, visit ready.lacounty.gov/heat for current locations and hours.
Los Angeles Public Library branches across the county serve as de facto cooling centers during extreme heat events, with their air-conditioned interiors, free wifi, and generally family-welcoming environments making them particularly valuable for households with children. The LAPL system at lapl.org shows current branch hours.
The Los Angeles County Department of Public Health also maintains a heat-related illness resource page at publichealth.lacounty.gov that includes current advisory status and symptoms guidance in multiple languages.
The Bottom Line
Today is Friday, March 20. The Extreme Heat Warning for inland Los Angeles County runs through 8 p.m. tonight. The Heat Advisory for the Malibu Coast and Los Angeles County Beaches runs through Saturday evening.
If you are going outside this weekend for any strenuous activity, start before 7 a.m. or go to the beach. Carry more water than you think you need. Know the symptoms of heat illness before you step onto a trail. And if the sun is high and you are starting to feel dizzy or weak, turn around immediately.
Los Angeles is in the middle of something genuinely rare. The trails will be there next weekend when the temperature returns to something more appropriate for spring. Your health is the thing worth protecting this weekend.
For current cooling center locations in Los Angeles County, visit ready.lacounty.gov/heat. For current National Weather Service advisories, visit weather.gov/lox. For heat illness symptoms and guidance, contact the LA County Public Health information line or visit publichealth.lacounty.gov.
