ZIP 78613 Zone 9a

Texas · USDA zone 9a, average annual extreme minimum 20°F to 25°F.

Nearest qualified station: AUSTIN GREAT HILLS, TX US (USC00410433), 7.1 miles from the Census ZCTA internal point for this ZIP.

Median last 32°F is March 11. Median first 32°F is November 20. The 50% growing-season length is 254 days. The green band runs from the median last frost to the median first frost. Thin ticks mark the 10%, 50%, and 90% dates.

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Last 32°F in spring

NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.

ProbabilityDateHow to read it
90%February 22Earlier date. A last 32°F on or after this day is common.
50%March 11Median.
10%March 29Later date. A last 32°F on or after this day is uncommon.

First 32°F in fall

NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.

ProbabilityDateHow to read it
10%November 3Earlier date. A first 32°F on or before this day is uncommon.
50%November 20Median.
90%December 9Later date. A first 32°F on or before this day is common.

32°F growing-season length

Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.

Probability the season is at least this longDays
10%278
50%254
90%230

28°F threshold

10%50%90%
Last, on or afterMarch 19March 1January 31
First, on or beforeNovember 12December 3December 29
Season at least309 days278 days252 days

36°F threshold

10%50%90%
Last, on or afterApril 11March 25March 6
First, on or beforeOctober 27November 10November 27
Season at least256 days231 days207 days

Station AUSTIN GREAT HILLS, TX US (USC00410433). Completeness flag R, 13 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 100%. Freeze dates are conditional on that threshold occurring. Elevation 268.2 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

Methodology · Texas cities