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USDA Hardiness Zone 9a

Frost Dates for 78741 — Austin, Texas

NOAA 1991–2020 normals from Austin 6S, TX (570 ft), 1 miles southwest.

Updated

In Austin, the last spring frost (32°F) is around March 10 in half of years and has passed by March 31 in nine years out of ten. The first fall frost comes around November 17, as early as November 1 one year in ten, leaving a typical freeze-free season of 252 days (NOAA, Austin 6S, TX).

Last spring frost
March 10

50% probability

First fall frost
November 17

50% probability

Growing season
252 days

freeze-free, 50%

Hardiness zone
9a

20 to 25°F (-6.7 to -3.9°C) coldest night

First snow
Rare

median, 1991–2020

Last snow
Rare

median, 1991–2020

Winters with snow
27%

6 of 22 observed

Snow per year
0.2"

NOAA normal

Frost risk by date in Austin

Half of springs at Austin 6S, TX see their last 32°F night by March 10; only one in ten is past it by February 20, and one in ten still has one after March 31. Planting tender crops after March 18 leaves a 30% risk of a frost on them, after March 24 20%, and after March 31 10%. The 21 days between the even-odds date and the one-in-ten date is wider than at 50% of the 339 Texas stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.

In fall the first 32°F night comes by November 17 in half of years, as early as November 1 one year in ten, and holds off past December 6 one year in ten. A hard freeze of 28°F follows 14 days later, around December 1; in spring the one-in-ten date for 28°F is March 17, 14 days before the 32°F one. The freeze-free season lasts 252 days in a typical year, longer than at 55% of the 339 Texas stations; it reaches 277 days one year in ten and falls short of 227 one year in ten. On average 29 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 15 days longer, to about March 25, and return around November 6. Nights of 24°F, cold enough to damage hardier plants, come in 95% of winters and 16°F in 19%.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°FMar 8Mar 13Mar 18Mar 21Mar 25Mar 31Apr 3Apr 7Apr 14
32°FFeb 20Feb 28Mar 3Mar 7Mar 10Mar 14Mar 18Mar 24Mar 31
28°FJan 29Feb 7Feb 15Feb 22Feb 28Mar 2Mar 6Mar 10Mar 17
24°F95% of yrsJan 6Jan 19Jan 26Feb 1Feb 6Feb 14Feb 23Mar 2Mar 7
20°F63% of yrsDec 21Jan 1Jan 8Jan 16Jan 21Jan 27Feb 2Feb 11Feb 26
16°F19% of yrstoo rare for a date
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°FOct 25Oct 30Nov 1Nov 3Nov 6Nov 9Nov 12Nov 16Nov 21
32°FNov 1Nov 5Nov 10Nov 14Nov 17Nov 21Nov 25Nov 30Dec 6
28°FNov 12Nov 18Nov 23Nov 28Dec 1Dec 5Dec 11Dec 18Dec 30
24°F95% of yrsNov 25Dec 2Dec 9Dec 15Dec 24Dec 29Jan 2Jan 9Jan 21
20°F63% of yrsDec 9Dec 18Dec 28Jan 1Jan 4Jan 9Jan 17Jan 25Feb 6
16°F19% of yrstoo rare for a date

Freeze probabilities 1991–2020 at Austin 6S, TX, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.

Frost risk on any date in 78741 →Compare Austin with another place →

Weather by month in Austin

August is the warmest month at Austin 6S, TX, averaging 97°F by day and 72°F at night; January is the coldest at 59°F and 37°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From April to October the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 75% of years.

Warmth for growing adds up to 6,708 growing degree days a year (base 50°F), more than at 62% of the 351 Texas stations. 41% of them (2,773) have built up by the end of June, and August adds the most, 1,054.

Monthly normals 1991–2020 at Austin 6S, TX
MonthHigh °FLow °F32°F nightNights ≤ 32°FGDD 50°F
Jan593799%1186
Feb644194%5145
Mar734875%1336
Apr79549%0509
May86630%0758
Jun93700%0939
Jul96720%01046
Aug97720%01054
Sep91660%0850
Oct81558%0571
Nov714680%3286
Dec633999%10127

Monthly normals 1991–2020 at Austin 6S, TX (570 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.

Compared with the next station

The nearest other station, Austin Bergstrom Airport, TX, 4 miles southeast of Austin, has a last frost 2 days later (March 12), a first frost 1 day earlier (November 16).

Frost dates for 78610 (Buda) →

When it snows in Austin, Texas

Measurable snow is rare here: only 6 of 22 winters from 1991 to 2020 recorded 0.1 inch or more at Austin Bergstrom Airport, TX, 4 miles away, so there is no typical first-snow date to plan around.

Planting calendar for 78741

What to do and when, from the 50% frost dates for Austin, Texas
WhenWhat to do
December 30 – January 13Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
January 13 – January 27Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
February 10 – February 24Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
March 10 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by August 25Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by November 3Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
November 17 onwardPlant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter.

The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.

Where these figures come from

ZIP 78741 is 1 mile from Austin 6S, TX, which stands at 570 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 11 other ZIP codes share the station; its figures are presented in full for 78745 (Austin). The 2023 USDA Plant Hardiness Zone Map lists ZIP 78741 in zone 9a, the band where the coldest night of the year averaged 20 to 25°F (-6.7 to -3.9°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Texas →

Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.

Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.

ZIP codes measured at the same station

Other zone 9a places in Texas