San Diego and beyond are great places to explore, but having some travel smarts can keep you out of trouble. Here are some safety guidelines meant to help you minimize your risks while exploring. This list is not meant to be all-inclusive.

Weather

There are four distinct climate zones in San Diego, and temperatures can vary almost 30° F / 16° C from the coast to the desert in the summer. Even in the summer, it can get cool enough along the waterfront to warrant a light jacket or sweater. Winter temperatures at elevation and in the deserts can drop to freezing or below. Dressing in layers and applying plenty of sunscreen will certainly make your visit more enjoyable.

Geology

Much of San Diego’s geology, especially along the coast, is a soft sandstone that can easily erode or weaken, especially after a rain. If you see a barrier or sign warning you to stay back from unstable cliff faces, please take the warning seriously. Sadly, there are too many reports of people having to be rescued from a cliff face after a fall, or worse. (One man fell 60 feet to his death on Christmas Day 2015 because he was distracted by his electronic device and didn’t pay attention to where he was going.

Desert Travel

The deserts east of San Diego are intriguing places to visit, but with summer temperatures that can soar as high as 120° F / 49° C, you can get into trouble very quickly if you are not prepared. Two tourists from Europe died in Joshua Tree National Park in August 2011 when they drove their rental car down a sandy road and got stuck in 105° F / 41° C heat.

• Stay on roads you know your car is capable of driving on.
• Bring plenty of water and snacks (that won’t melt in the heat) for each person in the vehicle.
• If in a national or state park, check with rangers for current conditions at the visitor center and let them know your plans.
• Beware of flash flooding during rain. Water and mud can even wash over paved highways.
• With scant or no cell phone service, about the only thing your smart phone will be good for is using its glass face as a signaling mirror.

Mountain Travel

Many of the mountain roads are twisting, turning, two-lane roads that will require snow chains on your drive tires when there is snow at elevation. You can check for current road conditions and restrictions on the Caltrans Quickmap.

Venomous Critters

The venomous spiders and snakes that call San Diego County home probably want as much to do with you as you do with them, so generally speaking, you’ll have little chance of encountering either.

The venomous spiders are the Black Widow, Brown Widow, and Desert Recluse.

Historically, the only venomous snakes we have in San Diego County have been four species of rattlesnakes: the Southern Pacific Rattlesnake, the Southwestern Speckled Rattlesnake, and the Red Diamond Rattlesnake, and the Colorado Desert Sidewinder. However, there have been two recent Southern California sightings—one on Coronado—of the highly venomous Yellow Bellied Sea Snake, a likely result of El Niño influences.

You can see rattlesnakes along the coast at Cabrillo National Monument, in urban canyons, and in the mountains and desert.

You can learn more about rattlesnakes here and about the Yellow Bellied Sea Snake here.