🎸 Austin Weather

On the edge of Flash Flood Alley

Austin sits right where the humid Gulf coastal plain runs up against the rugged Texas Hill Country, along a geographic feature called the Balcones Escarpment. That collision zone earns the region a stark nickname — "Flash Flood Alley" — making it one of the most flood-prone areas in North America, even as its sunny, hot climate draws people in droves.

Flash flooding and the Hill Country

When moist Gulf air is forced up over the Hill Country's hills, it can wring out enormous rainfall in a hurry. The thin soils and steep, rocky terrain shed water fast, turning creeks and the Colorado River into raging torrents within minutes. Spring and autumn are the prime seasons for these dangerous, sudden floods.

Long, hot summers

Summers are long, sunny, and hot, with highs in the upper 90s°F (around 36°C) from June well into September, and triple-digit stretches common in July and August. Winters are short and mild, with highs in the low 60s°F (around 17°C); freezes are occasional and usually brief.

Austin averages about 35 inches (890 mm) of rain a year, but it falls unevenly — long dry, hot spells punctuated by intense downpours, the boom-and-bust rainfall pattern typical of central Texas.

Hill Country heat and Flash Flood Alley

Austin's Central Texas summers are long and intense, with triple-digit heat that can persist for weeks and warm, humid nights. The Hill Country's thin soils and rocky terrain shed water fast, and the city sits squarely in 'Flash Flood Alley,' one of the most flood-prone regions in North America.

That flood risk turns dangerous when Gulf moisture stalls over the hills, as deadly Memorial Day and Halloween floods have shown. Winters are short and mild, but the rare Arctic blast — like February 2021 — brings ice that overwhelms the region's infrastructure and knocks out power.