USDA Hardiness Zone 6a
Frost Dates for 60457 — Hickory Hills, Illinois
NOAA 1991–2020 normals from Little Red School Hse, IL (715 ft), 3 miles west.
Updated
In Hickory 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
- First fall frost
- October 22
- Growing season
- 183 days
- Hardiness zone
- 6a
50% probability
50% probability
freeze-free, 50%
-10 to -5°F (-23.3 to -20.6°C) coldest night
- First snow
- December 3
- Last snow
- March 18
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
27 of 27 observed
NOAA normal
Frost risk by date in Hickory 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.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 16 | Apr 21 | Apr 25 | Apr 28 | Apr 30 | May 3 | May 6 | May 11 | May 18 |
| 32°F | Apr 6 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 21 | Apr 25 | Apr 30 | May 5 |
| 28°F | Mar 26 | Mar 31 | Apr 2 | Apr 4 | Apr 7 | Apr 9 | Apr 13 | Apr 17 | Apr 22 |
| 24°F | Mar 13 | Mar 19 | Mar 22 | Mar 26 | Mar 29 | Mar 31 | Apr 2 | Apr 5 | Apr 10 |
| 20°F | Mar 5 | Mar 9 | Mar 13 | Mar 16 | Mar 19 | Mar 22 | Mar 26 | Mar 29 | Apr 1 |
| 16°F | Feb 23 | Mar 2 | Mar 5 | Mar 8 | Mar 11 | Mar 14 | Mar 17 | Mar 20 | Mar 25 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 28 | Oct 3 | Oct 7 | Oct 9 | Oct 12 | Oct 14 | Oct 17 | Oct 20 | Oct 24 |
| 32°F | Oct 8 | Oct 14 | Oct 17 | Oct 19 | Oct 22 | Oct 24 | Oct 26 | Oct 29 | Nov 3 |
| 28°F | Oct 19 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 10 | Nov 16 |
| 24°F | Oct 31 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 22 | Nov 27 |
| 20°F | Nov 7 | Nov 11 | Nov 15 | Nov 18 | Nov 22 | Nov 24 | Nov 28 | Dec 2 | Dec 8 |
| 16°F | Nov 14 | Nov 19 | Nov 23 | Nov 27 | Nov 30 | Dec 2 | Dec 7 | Dec 13 | Dec 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 60457 →Compare Hickory Hills with another place →
Compared with the next station
The nearest other station, Chicago Midway Airport 3SW, IL, 3 miles east of Hickory Hills, has a last frost 9 days earlier (April 10), a first frost 10 days later (November 1), a season 20 days longer.
When it snows in Hickory Hills, Illinois
The first measurable snow (0.1 inch or more) in Hickory 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, 2.7 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 60457
| When | What to do |
|---|---|
| February 8 – February 22 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 22 – March 8 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 22 – April 5 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 19 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 30 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 8 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 22 onward | Plant 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 60457 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 60457 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.
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.