NWS Amarillo Climate Description
The station is located 7 statute miles east-northeast of the Amarillo downtown post office in a region of rather flat topography approximately 3,700 feet above mean sea level. The Canadian River flows eastward l8 miles north of the station, with its bed about 800 feet below the plains in places. The Prairie Dog Town Fork of the Red River flows southeastward about l5 miles south of the station where it enters the Palo Duro Canyon, which is about l,000 feet deep. There are numerous shallow Playa lakes, often dry, across the nearly treeless grasslands that slope downward to the east. The terrain gradually rises to the west and northwest.
Temperatures in the high plains vary greatly depending on the time of year. Average high temperatures in the summer rise into the low 90s with temperatures topping 100 degrees on average 5 times per year. High temperatures in the winter average in the upper 40s but can vary widely from the teens to the 70s or even 80 degrees (often accompanied by strong southwesterly winds). The average date of the first freezing temperatures in the fall is October 20. The average last freeze in the spring is April 18.
The Amarillo area is subject to extreme and rapid temperature changes, especially during the fall and winter months when cold fronts from the northern Rocky Mountain and Plains states sweep across the area. Temperature drops of 50 to 60 degrees within a 12-hour period are not uncommon. Temperature drops of 40 degrees have occurred within a few minutes.
Humidity averages are low, occasionally dropping below 15 percent in the spring. Low humidity moderates the effect of high summer afternoon temperatures, permits evaporative cooling systems to be very effective, and provides many pleasant evenings and nights.
The average anual precipitation for Amarillo is 19.71 inches. Three-fourths of the average precipitation falls from April through September, generally occurring with thunderstorm activity. Measurable precipitation falls on an average of 72 days per year, which averages out to a little more than once per week.
Severe local storms are infrequent throughout the cool season, but occasional thunderstorms with large hail, lightning, and damaging wind occur during the warm season, especially during the Spring. These storms are often accompanied by very heavy rain, which can produce local flooding, particularly of roads and streets. Tornadoes are most common from April to June.
The dryline is a feature which forms as a result of the gradually sloping terrain and warm, dry air flowing down from the southern Rocky Mountains. The dryline forms at the intersection of moist air on southeasterly winds from the Gulf of Mexico and warm, dry air on southwesterly winds. Thunderstorms can occur near the dryline and it is these thunderstorms which produce the majority of the tornadoes in the Southern Plains in the spring and early summer.
Snowfall averages 17.9 inches annually in Amarillo. Snow is most frequent during the winter months, but some of the heavier snowfalls have occurred in March. Roughly two thirds of winter precipitation falls in the form of snow. Snow has fallen as early as September and as late as May. Snow usually melts within a few days. Heavier snowfalls of 10 inches or more, often with near blizzard conditions, average once every 5 years and can last 2 to 3 days. Severe ice storms are uncommon, but freezing drizzle and freezing fog sometimes leave a light coating of ice during winter cold spells.
The Texas Panhandle is one of the windiest regions in the United States. As westerly winds flow over the Rocky Mountains, low pressure forms to the east of the mountains in the high plains. This very persistent low pressure is what leads to the strong average wind speeds from the southwest and west. Wind speeds of 50 mph or more occur each year, often with clear skies, warm temperatures, and blowing dust. These strong winds are most common in the winter and spring. Strong cold fronts can also bring northerly winds of 40 mph or more during the winter months. The windy conditions provide a perfect transport mechanism for one of the areas most well-known plants, the tumbleweed.