USDA Hardiness Zone 6a
Frost Dates for 60068 — Park Ridge, Illinois
NOAA 1991–2020 normals from Chicago Ohare International Airport, IL (658 ft), 5 miles west.
Updated
In Park Ridge, the last spring frost (32°F) is around April 16 in half of years and has passed by May 1 in nine years out of ten. The first fall frost comes around October 28, as early as October 15 one year in ten, leaving a typical freeze-free season of 193 days (NOAA, Chicago Ohare International Airport, IL).
- Last spring frost
- April 16
- First fall frost
- October 28
- Growing season
- 193 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
- November 17
- Last snow
- April 4
- Winters with snow
- 100%
- Snow per year
- 38.4"
median, 1991–2020
median, 1991–2020
29 of 29 observed
NOAA normal
Frost risk by date in Park Ridge
Half of springs at Chicago Ohare International Airport, IL see their last 32°F night by April 16; only one in ten is past it by April 3, and one in ten still has one after May 1. Planting tender crops after April 22 leaves a 30% risk of a frost on them, after April 26 20%, and after May 1 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 54% of the 158 Illinois stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 28 in half of years, as early as October 15 one year in ten, and holds off past November 11 one year in ten. A hard freeze of 28°F follows 10 days later, around November 7; in spring the one-in-ten date for 28°F is April 19, 12 days before the 32°F one. The freeze-free season lasts 193 days in a typical year, longer than at 77% of the 158 Illinois stations; it reaches 213 days one year in ten and falls short of 173 one year in ten. On average 121 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 13 days longer, to about April 29, and return around October 18. Severe cold of 16°F or below comes every winter, usually between December 3 and March 5.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 15 | Apr 20 | Apr 23 | Apr 26 | Apr 29 | May 1 | May 4 | May 8 | May 13 |
| 32°F | Apr 3 | Apr 8 | Apr 11 | Apr 14 | Apr 16 | Apr 19 | Apr 22 | Apr 26 | May 1 |
| 28°F | Mar 21 | Mar 27 | Mar 31 | Apr 2 | Apr 5 | Apr 7 | Apr 10 | Apr 14 | Apr 19 |
| 24°F | Mar 7 | Mar 13 | Mar 17 | Mar 21 | Mar 24 | Mar 28 | Mar 31 | Apr 3 | Apr 8 |
| 20°F | Feb 26 | Mar 2 | Mar 6 | Mar 10 | Mar 13 | Mar 16 | Mar 20 | Mar 24 | Mar 29 |
| 16°F | Feb 17 | Feb 24 | Feb 28 | Mar 2 | Mar 5 | Mar 8 | Mar 11 | Mar 15 | Mar 19 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 3 | Oct 8 | Oct 11 | Oct 15 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 30 |
| 32°F | Oct 15 | Oct 20 | Oct 24 | Oct 26 | Oct 28 | Oct 31 | Nov 3 | Nov 5 | Nov 11 |
| 28°F | Oct 27 | Nov 1 | Nov 2 | Nov 5 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 22 |
| 24°F | Nov 3 | Nov 7 | Nov 11 | Nov 14 | Nov 17 | Nov 20 | Nov 23 | Nov 27 | Dec 2 |
| 20°F | Nov 10 | Nov 15 | Nov 19 | Nov 23 | Nov 26 | Nov 29 | Dec 2 | Dec 6 | Dec 14 |
| 16°F | Nov 18 | Nov 25 | Nov 28 | Dec 1 | Dec 3 | Dec 7 | Dec 12 | Dec 17 | Dec 23 |
Freeze probabilities 1991–2020 at Chicago Ohare International Airport, 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 60068 →Compare Park Ridge with another place →
Weather by month in Park Ridge
July is the warmest month at Chicago Ohare International Airport, IL, averaging 85°F by day and 66°F at night; January is the coldest at 32°F and 19°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 10% of years.
Warmth for growing adds up to 3,331 growing degree days a year (base 50°F), fewer than at 63% of the 158 Illinois stations. 33% of them (1,095) have built up by the end of June, and July adds the most, 789. Precipitation totals 38.0 inches a year, most in May (4.5") and least in January (2.0"); May to September bring 52% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 32 | 19 | 2.0 | 100% | 28 | 1 |
| Feb | 36 | 22 | 2.0 | 100% | 24 | 3 |
| Mar | 47 | 31 | 2.5 | 100% | 20 | 30 |
| Apr | 59 | 40 | 3.8 | 93% | 6 | 105 |
| May | 71 | 51 | 4.5 | 10% | <1 | 338 |
| Jun | 80 | 61 | 4.1 | 0% | 0 | 618 |
| Jul | 85 | 66 | 3.7 | 0% | 0 | 789 |
| Aug | 83 | 65 | 4.3 | 0% | 0 | 738 |
| Sep | 76 | 57 | 3.2 | 0% | <1 | 491 |
| Oct | 63 | 45 | 3.4 | 62% | 3 | 185 |
| Nov | 48 | 34 | 2.4 | 100% | 15 | 32 |
| Dec | 37 | 24 | 2.1 | 100% | 25 | 3 |
Monthly normals 1991–2020 at Chicago Ohare International Airport, IL (658 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, Chicago Palwaukee Airport, IL, 8 miles northwest of Park Ridge, has a last frost 3 days later (April 19), a first frost 2 days earlier (October 26), a season 3 days shorter.
When it snows in Park Ridge, Illinois
The first measurable snow (0.1 inch or more) in Park Ridge usually arrives around November 17, and the last of the season around April 4. Those are the middle dates across the winters of 1991–2020 at Chicago Ohare International Airport, IL, 4.9 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 12 days after the last snow.
Planting calendar for 60068
| When | What to do |
|---|---|
| February 5 – February 19 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 19 – March 5 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 19 – April 2 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 16 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 5 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 14 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 28 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 60068 is 5 miles from Chicago Ohare International Airport, IL, which stands at 658 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 26 other ZIP codes share the station; its figures are presented in full for 60634 (Chicago). The 2023 USDA Plant Hardiness Zone Map lists ZIP 60068 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.