Texas climate map
Sheet TX-17 · rainfall ~56 in (far east) → under 10 in (El Paso) · 4 Köppen zones
One number explains most of the Texas climate map: annual rainfall, which falls steadily from about 56 inches a year in the pine country near the Sabine to under 10 inches at El Paso. Everything else — which trees grow, where ranching replaces farming, why the eastern half is green and the western half is brown — follows that line across the state.
Statewide view. Rainfall decreases from right to left across this map at roughly one inch per 15 miles of westward travel.
The rainfall gradient
Moisture arrives in Texas from the Gulf, so the wettest ground is the corner closest to it and the driest is the corner farthest away. Around Orange, Beaumont and the lower Sabine the long-term average runs near 56 inches; at El Paso, 800 miles west, it is 9.7 inches. The drop is remarkably even, close to one inch for every 15 miles travelled west.
Two lines on that gradient matter. The 30-inch line runs near the I-35 corridor, which is roughly where row-crop farming without irrigation stops being reliable. The 20-inch line runs near the 100th meridian — the old dividing line between the humid east and the arid west, and the reason West Texas is usually said to begin somewhere between Abilene and San Angelo. West of it, land is measured in sections rather than acres because it takes that much to run cattle.
Rain also changes character across the state. East Texas gets steady frontal rain spread through the year. The Hill Country and the plains get most of theirs in a handful of convective storms, so a place averaging 25 inches may take eight of them in one September night and nothing for two months.
Köppen zones
| Zone | Where | What it means |
|---|---|---|
| Cfa — humid subtropical | Everything east of a rough line from Wichita Falls through Austin to Del Rio | Hot humid summers, mild winters, rain in every month; pine, oak and prairie |
| BSh — hot semi-arid steppe | The Rio Grande plain and the southern plateau: Laredo, Del Rio, San Angelo | 15–25 inches of rain, very hot summers, frost uncommon; mesquite and brush |
| BSk — cold semi-arid steppe | The High Plains and Permian Basin: Amarillo, Lubbock, Midland | Same dryness, but elevation gives hard freezes, snow and large day-to-night swings |
| BWh — hot desert | The Trans-Pecos below the mountains: El Paso, Presidio, Pecos | Under 12 inches, most of it in a July–September monsoon; creosote and yucca |
The mountain ranges of the Big Bend and the Davis Mountains break the pattern: at 6,000–8,000 ft they are cooler and wetter than the desert around them.
City averages
| City | Annual rain (in) | Jan avg high (°F) | July avg high (°F) |
|---|---|---|---|
| Beaumont | 56 | 62 | 92 |
| Houston | 50 | 63 | 94 |
| Tyler | 46 | 56 | 93 |
| Dallas – Fort Worth | 38 | 57 | 96 |
| Waco | 36 | 58 | 96 |
| Austin | 34 | 62 | 96 |
| San Antonio | 33 | 63 | 95 |
| Corpus Christi | 31 | 67 | 94 |
| Wichita Falls | 30 | 52 | 98 |
| Brownsville | 27 | 70 | 93 |
| Abilene | 24 | 56 | 96 |
| San Angelo | 21 | 59 | 96 |
| Amarillo | 20 | 50 | 91 |
| Laredo | 20 | 68 | 100 |
| Lubbock | 19 | 54 | 92 |
| Del Rio | 19 | 63 | 98 |
| Midland | 15 | 58 | 94 |
| El Paso | 9.7 | 58 | 95 |
Long-term averages rounded to the nearest inch and degree. Individual years vary widely, especially for rainfall in the western half of the state.
Heat, cold and the seasons
July highs are within a few degrees of each other almost everywhere except the coast and the high plains, which is the surprise in the table: El Paso in the desert and Beaumont in the swamp are both in the nineties. What separates them is humidity at night and the length of the season. Laredo is the reliable hot spot, averaging about 100 °F in July.
Winter is where the state actually splits. Brownsville averages a January high near 70 °F and goes years without a hard freeze; Amarillo averages 50 °F and gets about 18 inches of snow in a season. Cold reaches Texas as a "blue norther", a front that sweeps south down the plains and can drop the temperature 30 degrees in an hour, then dies out over the Valley a day later.
The growing season stretches from roughly six months in the northern Panhandle to nearly year-round in the Rio Grande Valley, which is why citrus and sugarcane grow there and wheat and sorghum grow up north.
Storms
Hurricane season runs from 1 June to 30 November, with the greatest risk to the Texas coast in August and September. In 2017 Harvey stalled over the upper coast and dropped 60.58 inches of rain near Nederland, the most ever recorded from a tropical cyclone in the United States.
Tornadoes concentrate in the northern half of the state and peak between April and June, with the Red River counties on the southern end of the classic tornado corridor. A separate hazard belt, often called Flash Flood Alley, follows the Balcones Escarpment from Del Rio through San Antonio and Austin to Waco: thin soil over limestone sheds water instantly, and creeks there rise faster than almost anywhere in the country. Drought is the slow hazard — the 1950s drought remains the benchmark against which every dry spell in Texas is measured.
Extremes on record: 120 °F, reached at Seymour in 1936 and again at Monahans in 1994, and −23 °F, recorded at Tulia in 1899 and Seminole in 1933.