Extreme Heat Prompts Trail Closures and Safety Warnings in San Diego

San Diego County has closed three hiking trails for August due to extreme heat, urging hikers to stay safe with proper planning, hydration, and early starts.

1 minute read

August 4, 2025, 9:00 AM PDT

By Clement Lau


Poway, California

Autumn Sky Photography /

San Diego County has temporarily closed three popular hiking areas — El Capitan Preserve, Hellhole Canyon, and Mount Gower — for the month of August due to dangerous heat conditions. As Alex Lai reports, the annual closures are aimed at protecting hikers from heat-related emergencies and give park staff time to perform maintenance on the trails. Additional parks near the Anza-Borrego Desert, including Agua Caliente and Vallecito, have been closed since May and are set to reopen by Labor Day weekend.

Despite the closures, many hikers are still heading to other open trails such as Iron Mountain in Poway. Hikers like Annie and Nathan emphasize the importance of early starts, hydration, and sun protection — practices that can significantly reduce heat risks. CAL FIRE officials, however, continue to respond to frequent heat-related rescues, some of which require air support due to the remote locations and physical condition of those needing help.

Authorities urge all hikers, especially beginners, to be cautious during elevated temperatures and to plan ahead. Safety tips include wearing loose, light-colored clothing, packing extra water and electrolyte-replacement drinks, and avoiding peak heat hours. The closed trails are expected to reopen on September 1, but officials stress that heat safety should be a priority year-round.

Saturday, August 2, 2025 in CBS8

Young Professional

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban and Environmental Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban and Environmental Planner

Get top-rated, practical training for planners

"Planetizen federal action tracker" logo superimposed over black and white image of US Capitol dome.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

September 16, 2026 - Zachary Whalen

Overlapping highways

The state-sanctioned urbicide of Austin

People don’t kill cities. Freeways do.

September 8, 2026 - Benjamin Schneider

The Hoover Dam blocking the Colorado River. The river's water level is noticeably low. The cliffs surrounding the blue water are brown and jagged.

US to reduce Colorado River water deliveries to Mexico

A new Colorado Treaty amendment reduces Mexico’s Colorado River water allocation by 250,000 acre feet.

September 11, 2026 - The Arizona Republic

A cluster of wind turbines beneath a stormy sky, above a forest where the leaves are beginning to change colors.

5 New England states march closer to 800 megawatt wind energy project

Securing federal approval for the project may be complicated under the Trump administration, which has historically been hostile towards domestic wind power.

6 hours ago - Inside Climate News

People boarding a bus on Maryland's Orange Route.

Baltimore to break ground on $50 million Transit Priority Project

The project will bring faster bus trips, safer streets and better bike connections to Baltimore.

7 hours ago - Mass Transit

A brick building with a circular sign with the Airbnb logo hanging off of it.

Airbnb launches $250 million 'last-dollar financing' housing accelerator, makes first investment in Austin

The company will put $6.4 million towards affordable housing development in Texas’ capital.

September 16 - Smart Cities Dive

FREE Course: Walkable City 1: Why Walkability?

After describing his path towards focusing on walkability as the essence of good planning, Jeff Speck marches through his five principal reasons for making more walkable places.

Reinventing Malls: Planning Alchemy—Turning Gray Fields Into Gold

The course focuses on the opportunities and imperatives that shape reinvention of mall sites.