US Grow Zones

Provo, Utah: planting zone & frost dates

Last updated · Sources: PRISM/OSU 2023 ZIP zone listings; NOAA NCEI 1991–2020 Climate Normals (station USC00427064); U.S. Census Bureau — see methodology

Provo is in USDA plant hardiness zone 6b, where the average coldest winter night reaches -5 to 0°F (-20.6 to -17.8°C). The typical last spring frost is around Apr 25 and the first fall frost around Oct 16.

Hardiness zone6B-5 to 0°F
Last spring frostApr 2530% chance of frost after
First fall frostOct 1630% chance of frost before
Growing season185 daysmedian frost-free days

Frost dates

ProbabilityLast spring frost (32°F)First fall frost (32°F)
Safer (10% risk)May 5Oct 7
Typical planning date (30% risk)Apr 25Oct 16
Median (50%)Apr 18Oct 21

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 PROVO BYU, UT (USC00427064), 0.3 mi (0.5 km) from the city center and 36 ft lower than the city center (-11 m). Record used for the 1991–2020 normals: 30 years.

Frost probability in spring and fall, Provo, UTChance of a 32°F frost in Provo, UT, NOAA 1991–2020. Spring: the chance of another frost falls from 90% on Mar 31 to 10% on May 5. Fall: the chance that the first frost has arrived rises from 10% on Oct 7 to 90% on Nov 4.0%50%100%Spring: later frostMar 1Apr 1May 130%: Apr 25Fall: frost arrivedOct 1Oct 15Nov 1Nov 1530%: Oct 1632°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 USC00427064.
Frost-free growing season in Provo, UT1 in 10 risk: May 5 to Oct 7 (155 days); 3 in 10 risk: Apr 25 to Oct 16 (174 days); Median (50%): Apr 18 to Oct 21 (186 days); No 28°F freeze: Mar 31 to Nov 1 (215 days). In 9 of 10 years the 32°F-free season is at least 163 days.Frost-free days, spring to fallJFMAMJJASOND1 in 10 risk155 days3 in 10 risk174 daysMedian (50%)186 daysNo 28°F freeze215 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 Provo

Provo spans more than one half-zone. Share of the city's land area by zone (via its 4 ZIP codes): 6b (54%), 7a (46%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.

ZIP codes in Provo and their zones
ZIPZoneShare of city land
846046b50.9%
846017a29.2%
846067a16.5%
846636b2.9%

Vegetable planting calendar for Provo

Dates are counted from the 30%-risk frost dates above (last frost Apr 25, first frost Oct 16). Shift a week later in cold spots or low-lying ground.

CropStart indoorsTransplant / plant outDirect sowFall crop sow/plant
TomatoFeb 28 – Mar 14May 2 – May 16——
PepperFeb 14 – Feb 28May 9 – May 23——
LettuceMar 14 – Mar 28Apr 11 – May 2Mar 28 – May 9Aug 7 – Sep 4
Green Beans——May 2 – Jun 6Jul 24 – Aug 7
Sweet Corn——May 2 – May 30—
Zucchini & Summer SquashMar 28 – Apr 4May 2 – May 16May 2 – May 23Jul 24 – Aug 7
CucumberMar 28 – Apr 4May 9 – May 16May 2 – May 23Jul 24 – Aug 7
Carrot——Apr 4 – May 9Jul 24 – Aug 7
OnionJan 31 – Feb 14Mar 28 – Apr 11——
Potato—Mar 28 – Apr 18——
BasilMar 14 – Mar 28May 9 – May 23May 9 – May 30—
Spinach——Mar 14 – Apr 11Aug 21 – Sep 18
KaleFeb 28 – Mar 14Mar 28 – Apr 18Mar 28 – Apr 18Aug 7 – Sep 4
BroccoliFeb 28 – Mar 14Apr 11 – May 2—Jul 24 – Aug 7
Peas——Mar 14 – Apr 4Aug 7 – Aug 21
EggplantFeb 14 – Feb 28May 9 – May 23——
CabbageFeb 28 – Mar 14Mar 28 – Apr 11—Jul 24 – Aug 7
Radish——Mar 21 – May 9Sep 4 – Oct 2
Strawberry—Mar 28 – Apr 18——
Beets——Apr 4 – May 16Aug 7 – Aug 21

Nearby cities in Utah

More: all Utah cities · other zone 6b cities: Columbus, OH, Indianapolis, IN, Boston, MA, Detroit, MI, Kansas City, MO, Cincinnati, OH, Pittsburgh, PA, Buffalo, NY

Provo gardening questions

When is the last frost in Provo, UT?

Plan around Apr 25. At NOAA's Provo Byu, UT station, 0.3 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 Apr 18, and after May 5 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Mar 31. The 90% and 10% dates are 35 days apart, close to the 36-day median for cities on this site.

When should I plant tomatoes in Provo, UT?

Start seeds indoors Feb 28 – Mar 14 and set transplants outside May 2 – May 16, once nights stay above 50°F and the soil is near 60°F. That leaves 174 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 Provo?

About 185 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 163 days, and in 1 year in 10 it runs 208 days or more. In fall there is a 10% chance of frost by Oct 7 and a 30% chance by Oct 16. That ranks 5th longest of 11 Utah cities on this site.

When should I plant a fall garden in Provo?

Count back from the first fall frost (Oct 16): transplant broccoli Jul 24 – Aug 7; sow kale Aug 7 – Sep 4; sow lettuce Aug 7 – Sep 4; sow radishes Sep 4 – Oct 2. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 1. How the math works: succession and fall planting.

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

Yes, but toward colder: Provo went from zone 7a (2012) to zone 6b (2023). Only about 1% of U.S. ZIP codes moved colder; these changes mostly reflect added weather stations and improved mapping methods rather than a colder climate. Why the 2023 map is warmer.

Is all of Provo in zone 6b?

No. Zone 6b covers about 54% of the city's land; the rest is in 7a (46%), measured across the city's 4 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.