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USDA Hardiness Zone 6a

Frost Dates for 60465 — Palos Hills, Illinois

NOAA 1991–2020 normals from Little Red School Hse, IL (715 ft), 3 miles west.

Updated

In Palos Hills, the last spring frost (32°F) is around April 19 in half of years and has passed by May 5 in nine years out of ten. The first fall frost comes around October 22, as early as October 8 one year in ten, leaving a typical freeze-free season of 183 days (NOAA, Little Red School Hse, IL).

Last spring frost
April 19

50% probability

First fall frost
October 22

50% probability

Growing season
183 days

freeze-free, 50%

Hardiness zone
6a

-10 to -5°F (-23.3 to -20.6°C) coldest night

First snow
December 3

median, 1991–2020

Last snow
March 18

median, 1991–2020

Winters with snow
100%

27 of 27 observed

Snow per year
—

NOAA normal

Frost risk by date in Palos Hills

Half of springs at Little Red School Hse, IL see their last 32°F night by April 19; only one in ten is past it by April 6, and one in ten still has one after May 5. Planting tender crops after April 25 leaves a 30% risk of a frost on them, after April 30 20%, and after May 5 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 22% of the 158 Illinois stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 22 in half of years, as early as October 8 one year in ten, and holds off past November 3 one year in ten. A hard freeze of 28°F follows 10 days later, around November 1; in spring the one-in-ten date for 28°F is April 22, 13 days before the 32°F one. The freeze-free season lasts 183 days in a typical year, shorter than at 53% of the 158 Illinois stations; it reaches 203 days one year in ten and falls short of 163 one year in ten. On average 131 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 11 days longer, to about April 30, and return around October 12. Severe cold of 16°F or below comes every winter, usually between November 30 and March 11.

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

Freeze probabilities 1991–2020 at Little Red School Hse, IL, 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 60465 →Compare Palos Hills with another place →

Compared with the next station

The nearest other station, Chicago Midway Airport 3SW, IL, 4 miles northeast of Palos Hills, has a last frost 9 days earlier (April 10), a first frost 10 days later (November 1), a season 20 days longer.

Frost dates for 60628 (Chicago) →

When it snows in Palos Hills, Illinois

The first measurable snow (0.1 inch or more) in Palos Hills usually arrives around December 3, and the last of the season around March 18. Those are the middle dates across the winters of 1991–2020 at Little Red School Hse, IL, 2.5 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 32 days after the last snow.

Planting calendar for 60465

What to do and when, from the 50% frost dates for Palos Hills, Illinois
WhenWhat to do
February 8 – February 22Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
February 22 – March 8Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 22 – April 5Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 19 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 30Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 8Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 22 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 60465 is 3 miles from Little Red School Hse, IL, which stands at 715 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 10 other ZIP codes share the station; its figures are presented in full for 60462 (Orland Park). The 2023 USDA Plant Hardiness Zone Map lists ZIP 60465 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Illinois →

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 6a places in Illinois