US Grow Zones

Allen, Texas: planting zone & frost dates

Last updated · Sources: PRISM/OSU 2023 ZIP zone listings; NOAA NCEI 1991–2020 Climate Normals (station USW00053914); U.S. Census Bureau — see methodology

Allen is in USDA plant hardiness zone 8b, where the average coldest winter night reaches 15 to 20°F (-9.4 to -6.7°C). The typical last spring frost is around Mar 27 and the first fall frost around Nov 5.

Hardiness zone8B15 to 20°F
Last spring frostMar 2730% chance of frost after
First fall frostNov 530% chance of frost before
Growing season239 daysmedian frost-free days

Frost dates

ProbabilityLast spring frost (32°F)First fall frost (32°F)
Safer (10% risk)Apr 7Oct 27
Typical planning date (30% risk)Mar 27Nov 5
Median (50%)Mar 18Nov 11

How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.

Frost data comes from NOAA station MCKINNEY MUNI AP, TX (USW00053914), 6.8 mi (11.0 km) from the city center and 75 ft lower than the city center (-23 m). Record used for the 1991–2020 normals: 21 years.

Frost probability in spring and fall, Allen, TXChance of a 32°F frost in Allen, TX, NOAA 1991–2020. Spring: the chance of another frost falls from 90% on Feb 28 to 10% on Apr 7. Fall: the chance that the first frost has arrived rises from 10% on Oct 27 to 90% on Dec 1.0%50%100%Spring: later frostFeb 15Mar 1Mar 15Apr 130%: Mar 27Fall: frost arrivedNov 1Nov 15Dec 1Dec 1530%: Nov 532°F frost28°F hard freezeplanning date
Shaded areas show the chance of a 32°F frost: falling through spring, rising through fall. The dashed line is the 28°F hard-freeze curve. Data: NOAA 1991–2020 Normals, station USW00053914.
Frost-free growing season in Allen, TX1 in 10 risk: Apr 7 to Oct 27 (203 days); 3 in 10 risk: Mar 27 to Nov 5 (223 days); Median (50%): Mar 18 to Nov 11 (238 days); No 28°F freeze: Mar 4 to Nov 24 (265 days). In 9 of 10 years the 32°F-free season is at least 211 days.Frost-free days, spring to fallJFMAMJJASOND1 in 10 risk203 days3 in 10 risk223 daysMedian (50%)238 daysNo 28°F freeze265 days
Frost-free window at three risk levels, plus the window between 28°F hard freezes. Read about what the probabilities mean.

Why your yard may differ from the station: microclimates.

Hardiness zone across Allen

All 2 ZIP codes covering Allen are in zone 8b.

ZIP codes in Allen and their zones
ZIPZoneShare of city land
750138b56.9%
750028b43.1%

Vegetable planting calendar for Allen

Dates are counted from the 30%-risk frost dates above (last frost Mar 27, first frost Nov 5). Shift a week later in cold spots or low-lying ground.

CropStart indoorsTransplant / plant outDirect sowFall crop sow/plant
TomatoJan 30 – Feb 13Apr 3 – Apr 17——
PepperJan 16 – Jan 30Apr 10 – Apr 24——
LettuceFeb 13 – Feb 27Mar 13 – Apr 3Feb 27 – Apr 10Aug 27 – Sep 24
Green Beans——Apr 3 – May 8Aug 13 – Aug 27
Sweet Corn——Apr 3 – May 1—
Zucchini & Summer SquashFeb 27 – Mar 6Apr 3 – Apr 17Apr 3 – Apr 24Aug 13 – Aug 27
CucumberFeb 27 – Mar 6Apr 10 – Apr 17Apr 3 – Apr 24Aug 13 – Aug 27
Carrot——Mar 6 – Apr 10Aug 13 – Aug 27
OnionJan 2 – Jan 16Feb 27 – Mar 13——
Potato—Feb 27 – Mar 20——
BasilFeb 13 – Feb 27Apr 10 – Apr 24Apr 10 – May 1—
Spinach——Feb 13 – Mar 13Sep 10 – Oct 8
KaleJan 30 – Feb 13Feb 27 – Mar 20Feb 27 – Mar 20Aug 27 – Sep 24
BroccoliJan 30 – Feb 13Mar 13 – Apr 3—Aug 13 – Aug 27
Peas——Feb 13 – Mar 6Aug 27 – Sep 10
EggplantJan 16 – Jan 30Apr 10 – Apr 24——
CabbageJan 30 – Feb 13Feb 27 – Mar 13—Aug 13 – Aug 27
Radish——Feb 20 – Apr 10Sep 24 – Oct 22
Strawberry—Feb 27 – Mar 20——
Beets——Mar 6 – Apr 17Aug 27 – Sep 10

Nearby cities in Texas

More: all Texas cities · other zone 8b cities: Dallas, TX, Fort Worth, TX, El Paso, TX, Virginia Beach, VA, Arlington, TX, Plano, TX, Irving, TX, Garland, TX

Allen gardening questions

When is the last frost in Allen, TX?

Plan around Mar 27. At NOAA's Mckinney Municipal Airport, TX station, 6.8 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Mar 18, and after Apr 7 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Mar 4. The 90% and 10% dates are 38 days apart, close to the 36-day median for cities on this site.

When should I plant tomatoes in Allen, TX?

Start seeds indoors Jan 30 – Feb 13 and set transplants outside Apr 3 – Apr 17, once nights stay above 50°F and the soil is near 60°F. That leaves 223 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.

How long is the growing season in Allen?

About 239 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 211 days, and in 1 year in 10 it runs 266 days or more. In fall there is a 10% chance of frost by Oct 27 and a 30% chance by Nov 5. That ranks 48th longest of 55 Texas cities on this site.

When should I plant a fall garden in Allen?

Count back from the first fall frost (Nov 5): transplant broccoli Aug 13 – Aug 27; sow kale Aug 27 – Sep 24; sow lettuce Aug 27 – Sep 24; sow radishes Sep 24 – Oct 22. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 24. How the math works: succession and fall planting.

Did Allen's hardiness zone change on the 2023 map?

Yes. Most of Allen was zone 8a on the 2012 map and is zone 8b on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.

How does Allen compare with Plano, TX?

Both are in zone 8b. The typical last spring frost in Allen (Mar 27) comes about 13 days later than in Plano, TX (Mar 14), 6 miles away, and the first fall frost is Nov 5 versus Nov 13. The two cities use different NOAA stations.