Big Bend is further south and west than most of Texas, and the region is often affected by weather originating in the Pacific Ocean, in contrast to the influence that the Gulf of Mexico has on much of the state. Weather conditions can be distinctly different than other parts of the state. To make things even more confusing, television weathermen stand in front of far west Texas as they point to the more populated parts of the state and country.

The following seasonal summaries may help plan a more enjoyable trip to the area. Remember the adage, " climate is what you expect; weather is what you get." Prepare for the worst imaginable scenario (as well as the best), and you'll always come out smiling. Seasons listed do not conform exactly to the equinoctial cycles, and conditions may overlap at the edges.

SPRING (Feb. through May) Spring like conditions can occur throughout the winter months, and some winters rarely see freezing temperatures. By mid February, especially at the lower elevations, mid day dress often reverts to shorts and T-shirts, although nights are still chilly, especially in the mountains and in the river valleys.

The weather usually warms up during March, and the desert lowlands may experience temperatures crowding 100 by the end of the month. The wind in these parts can be tough, and is always factor to be considered when planning outdoor activities.

Rain during March and April is not unheard of, and some years have enjoyed significant precipitation during these months. On April 5, 1982, daytime highs at Lajitas by the Rio Grande were 105. On April 12, it snowed down to the 3000' level; daytime high was 41f at the saame location. A light drizzle and winds of 30 knots brought the wind chill factor to polar extremes. May is a usually pretty dry, but you never can tell. On Mother's day 1983, a freak hail storm lasted over 20 minutes in the Study Butte/Terlingua area, with golf ball sized hail blowing almost sideways in 40 knot+ winds. Terlingua creek ran 6 feet deep with a foot thick layer of hailstones on the surface. Three days later, in 100+ temperatures, hikers found a large bank of as yet unmelted hailstones buried in a mud undercut.

Recommended outdoor apparel: Bring everything! Rain gear can be vital, along with insulating layers: wool or modern synthetics that still work if they get wet. Cotton is unsuitable for damp, windy conditions. Jeans are especially uncomfortable when wet. Don't forget the sun hat, shorts, T-shirts and beachwear. Most of the time, that's all you need, but be prepared for all contingencies if you want to guarantee a comfortable visit.

SUMMER (May-September) Summer like conditions can occur nearly year round. Record high for the Castolon station for the month of February is 102. Big Bend can be a hot place, and even during the non-summer months, be prepared for dry, hot conditions.

Typically June is the hottest month of the year, with May and July close 2nd and thirds. May and June are usually dry, but there are sometimes exceptions, such as in 2007, when plentifu rains have kept the desert green and the temperatures quite pleasant.

July can start out hot and muggy, but usually, afternoon clouds will start to build up into thunderheads, and scattered afternoon showers can cool things down significantly. By the end of July through the end of September, this afternoon pattern should be well established; we anticipate getting most of our annual rainfall during these months. Tropical storm season in the eastern Pacific should also be kicking in, and significant moisture can advect over the Sierra Madre and help quench the parched desert beyond. Hurricanes and tropical storms whose tracks veer west towards Texas can inundate the Rio Conchos drainage and occasion extreme high water in the Rio Grande.

August can be surprisingly cool, if the above factors come into play. During July 1998, the National Park area experienced several days where daytime highs were under 90, at a time when the rest of the state was experiencing record numbers of consecutive days above 100. Summertime can be the most rewarding time to visit Big Bend. Although hot, visitors who risk the trip can be rewarded with surprisingly mild temperatures, especially in the Chisos Mountains and Marathon areas, beautiful cloudy sunsets, evening thunderstorms and lightning shows, and the unequaled smell of the desert after a brisk rain.

Recommended outdoor apparel: Smart summer desert travelers wear a broad brimmed hat, long pants and long sleeved shirts. The ideal clothing is loose fitting, lightweight cotton. This strategy works well on the river, and there is nothing more cooling than dipping a shirt into the river and putting it back on. Shorts and T-shirts are also very common, but provide less than adequate protection from the sun and from the thorny plant life of the Chihuahuan Desert. Don't forget rain gear, and an extra insulating layer just in case you have the luck to be caught in a windy summer downpour.

Dehydration is a serious hazard in desert regions. Visitors who are accustomed to more humid climates often fail to realize how much moisture they are breathing out. Even without heavy exertion or breaking a sweat, one can lose up to two quarts of water from simply breathing dry desert air. This moisture must be replaced. Professional guides always plan on at the minimum of one gallon per person of water per day, and often use more. Always carry plenty of water: It is important to drink often, even before feeling thirsty. Learn and watch for the signs of dehydration, heat exhaustion, and heat stroke; and know what to do in such cases. This can save someone's life, maybe someone you know or love.

FALL (late September- mid December) Temperatures can still be warm well into October, but the nights are cooling down. Many consider fall to be the nicest time to visit Big Bend. The temperature range approaches a comfortable ideal, and in general it is less windy than the spring months. Like the spring months, however, both extremes can be seen, and visitors need to prepare accordingly.

A good rainy season can last well into the fall. Tropical moisture from the Gulf of California and the eastern Pacific may still be flowing into our area, and if this warm, moist air collides with an early season cold front (norther) the result can be torrential, cold rain. This rare event occurred during Chili Cook Off in early November 1980, when it rained several inches over a few. hours Traffic was stranded when every one of many local shallow water crossings filled with several feet of turbulent water. River levels at Lajitas approached 20 feet. 150 miles downstream in the Lower Canyons, the river at Dryden Crossing crested at almost 60 feet. For the well prepared, it was the experience of a lifetime.

Recommended outdoor apparel: Everything! (see SPRING). Besides the typical T-shirts and shorts, remember rain gear and insulating layers. Late fall visitors should plan for temperatures around freezing, although that is rarely the case.

WINTER (Late November-February) Although winter like conditions can occur as early as late October and as late as mid-April, that is not usually the case. Winters are usually dry and mild, although the occasional wet winter is welcomed as it makes for prolific wildflower blooms in the spring. A normal mid-winter day would be clear, with a daytime high of 65 or more, and an overnight low in the low 40's or high 30's. This pattern is broken a few times during the season when a "blue norther" blows in. Occasionally these storms bring precipitation, but usually it just gets cloudy and windy, with daytime highs AND overnight lows in the 40's. A norther will typically clear in a day or two, followed by an intensely clear high-pressure area. The daytime highs return quickly to T-shirt and shorts levels, but the overnight lows may plunge to freezing or below. It is not unusual to experience 40 and 50 temperature differences between dawn and early afternoon.

IMPORTANT NOTE Storms that coat Central and Northern Texas with ice, or lower temperatures to zeroin the panhandle, almost always dissipate most of their fury before getting as far south as the Rio Grande. Temperatures in Lajitas can be 20degrees higher than in places as close as Alpine or Marfa. People sometimes cancel their vacations based on inclement conditions predicted in their hometown, only to find out afterward that Big Bend saw little or no effect from that particular storm.

Recommended outdoor apparel: It is good to remember that cotton clothing will not keep a body warm when wet, and in fact, bare skin is better than wet cotton. Until mid 20th century, wool was the material of choice for cold, wet weather, but we now have synthetic materials that are almost entirely non-absorbent, retaining most of their insulating properties when wet. Polypropylene, polyester and other new fangled fabrics come in many different weaves and guises. A mind numbing array of products are available, everything from insulated underwear to heavy parkas. Considering that our area is mostly dry, down is favored by some outdoors people due to its excellent insulating properties and its minimum weight. It is important to know that down loses its ability to insulate when wet. A local wise man spoke "it seldom rains in the desert, but when it does, you get wet." Take heed.

Layering is an important concept. With the occasional extreme temperature changes of winter, it is not practical to simply have one heavy jacket; rather a series of layers: lightweight insulated underwear under a long sleeved shirt, under a sweater, under a jacket, under a wind or rain shell. As the day warms, layers can be removed one at a time to maintain comfort, and as the shadows lengthen, these layers can be replaced. Since almost 50% of body heat is lost through the head and neck, a warm hat is a vital part of the proper cold weather kit. Wool is the recommended material for socks, and some people use a lightweight polypropylene sock underneath their woollies for comfort. Spare dry socks can quickly turn into valuable trade items on winter trips. Once again, prepare for all imaginable extremes, bringing the shorts and T-shirts as well. You'll be glad you did. As most local guides will attest, winter camping trips can be fun; the relatively mild winters of Big Bend are a popular time for camping, hiking, bicycling, and river running. With careful preparation and a keen weather eye, visitors enjoy an almost endless outdoor season in the Big Bend of Texas.

On Line Weather Resources

Big Bend Weather Forecast

Rio Grande Flow Conditions