Weather and Climate

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The climate in San Bernardino varies throughout the region, as it covers such a large area. While the San Bernardino Valley is temperate, Twentynine Palms is a hot, desert climate. Temperatures can reach above 100 degrees in the summer months, while winters are mild with an average low of 41 degrees in January. The average rainfall is a scant 4.5 inches annually.

Fortunately, most evenings offer tolerable temperatures, allowing Twentynine Palms’ modernday desert dwellers to enjoy breathtaking sunsets and unsurpassed stargazing.

Sun Exposure
Some exposure to sunlight is good, even healthy, but too much can be dangerous. Broadspectrum ultraviolet (UV) radiation, listed as a known carcinogen by the National Institute of Environmental Health Science, can cause blistering sunburns, as well as long-term problems like skin cancer, cataracts and immune suppression. Overexposure also causes wrinkling and premature aging of the skin.

Cloud cover — which is sparse in Twentynine Palms — reduces UV levels but not completely. Depending on the thickness of the cloud cover, you can still burn on a cold and dim day. So be prepared with sunglasses, sunscreen, long-sleeved garments, wide-brimmed hats and an umbrella.

Heat Exposure
Because of Twentynine Palms and San Bernardino County’s high temperatures, it is important to take precautions to avoid heat exhaustion and heat stroke. Stay indoors when temperatures are extreme. Drink cool liquids often, particularly water, even if you do not feel thirsty. Avoid alcoholic beverages, as they dehydrate the body.

Eat small, frequent meals and avoid foods high in protein, as they increase metabolic heat. If you must venture outdoors, avoid going

out during midday hours. Wear lightweight, light-colored clothing to reflect sunlight. Avoid strenuous activities and keep hydrated. Cover all exposed skin with a high SPF sunscreen and follow general sun exposure precautions.

If you experience any of the following warning signs of heat stroke, seek out immediate medical attention:
• Body temperature above 103 degrees
• Red, hot and dry skin
• Rapid, strong pulse
• Throbbing headache
• Dizziness
• Nausea
• Confusion
• Unconsciousness

Flash Flooding
While Twentynine Palms enjoys rare precipitation, a single thunderstorm can deliver threequarters of the annual rainfall. Generally, areas like Twentynine Palms do not have storm drains, culverts and other water-diverting infrastructure. Desert sand is poorly absorbent and dry channels, ditches and lake beds fill quickly. This can lead to flash-flood conditions.

If you are outdoors during a rainstorm, seek higher ground. Avoid walking through any floodwaters — even water six inches deep can sweep you off your feet. If you are driving, avoid flooded areas. The majority of deaths in a flash flood occur when people drive through flooded areas. Roads concealed by water may not be intact. Water only a foot deep can displace a vehicle. If your vehicle stalls, leave it immediately and seek higher ground.

Rapidly rising water can engulf a vehicle and sweep it away.

A flash flood watch is issued when flash flooding is expected to occur within six hours after heavy rains have ended. A flash flood warning is issued for life- and property-threatening flooding that will occur within six hours.

During a flash flood watch or warning, stay tuned to local radio or TV stations or a National Oceanographic and Atmospheric Administration (NOAA) Weather Radio for further weather information.

Southern California has thousands of earthquakes every year. Fortunately, most do not cause damage or are even felt. However, it is important to be prepared for an earthquake. Identify potential hazards in your home. Secure top-heavy furniture to a wall. Use earthquake putty on hanging pictures and mirrors. Secure objects on shelves that could become projectiles during an earthquake.

In the case of an earthquake, remember: drop, cover and hold on. If you are not near a table or desk, drop to the floor against an interior wall and protect your head and neck with your arms. Avoid exterior walls, windows, hanging objects, mirrors and other objects that could fall. For more information on earthquake preparedness, visit www.earthquakecountry.info.


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