USDA Hardiness Zone 5b
Frost Dates for 60098 — Woodstock, Illinois
NOAA 1991–2020 normals from Crystal Lake 4NW, IL (940 ft), 4 miles southeast.
Updated
In Woodstock, the last spring frost (32°F) is around April 25 in half of years and has passed by May 9 in nine years out of ten. The first fall frost comes around October 22, as early as October 7 one year in ten, leaving a typical freeze-free season of 179 days (NOAA, Crystal Lake 4NW, IL).
- Last spring frost
- April 25
- First fall frost
- October 22
- Growing season
- 179 days
- Hardiness zone
- 5b
50% probability
50% probability
freeze-free, 50%
-15 to -10°F (-26.1 to -23.3°C) coldest night
- First snow
- November 22
- Last snow
- April 8
- Winters with snow
- 100%
- Snow per year
- 35.1"
median, 1991–2020
median, 1991–2020
26 of 26 observed
NOAA normal
Frost risk by date in Woodstock
Half of springs at Crystal Lake 4NW, IL see their last 32°F night by April 25; only one in ten is past it by April 11, and one in ten still has one after May 9. Planting tender crops after May 1 leaves a 30% risk of a frost on them, after May 4 20%, and after May 9 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 82% 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 7 one year in ten, and holds off past November 4 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 27, 12 days before the 32°F one. The freeze-free season lasts 179 days in a typical year, shorter than at 65% of the 158 Illinois stations; it reaches 198 days one year in ten and falls short of 158 one year in ten. On average 136 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 10 days longer, to about May 5, and return around October 11. Severe cold of 16°F or below comes every winter, usually between November 29 and March 13.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 23 | Apr 27 | Apr 30 | May 2 | May 5 | May 8 | May 11 | May 15 | May 21 |
| 32°F | Apr 11 | Apr 16 | Apr 19 | Apr 22 | Apr 25 | Apr 28 | May 1 | May 4 | May 9 |
| 28°F | Mar 31 | Apr 4 | Apr 7 | Apr 10 | Apr 12 | Apr 15 | Apr 19 | Apr 22 | Apr 27 |
| 24°F | Mar 17 | Mar 22 | Mar 27 | Mar 31 | Apr 2 | Apr 4 | Apr 7 | Apr 10 | Apr 15 |
| 20°F | Mar 7 | Mar 12 | Mar 16 | Mar 19 | Mar 21 | Mar 24 | Mar 28 | Mar 31 | Apr 4 |
| 16°F | Feb 26 | Mar 3 | Mar 6 | Mar 10 | Mar 13 | Mar 16 | Mar 18 | Mar 22 | Mar 28 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 25 | Oct 1 | Oct 5 | Oct 8 | Oct 11 | Oct 14 | Oct 16 | Oct 19 | Oct 24 |
| 32°F | Oct 7 | Oct 13 | Oct 17 | Oct 19 | Oct 22 | Oct 25 | Oct 27 | Oct 30 | Nov 4 |
| 28°F | Oct 20 | Oct 25 | Oct 28 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 15 |
| 24°F | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 12 | Nov 14 | Nov 17 | Nov 21 | Nov 26 |
| 20°F | Nov 7 | Nov 11 | Nov 15 | Nov 18 | Nov 21 | Nov 24 | Nov 27 | Dec 1 | Dec 5 |
| 16°F | Nov 13 | Nov 19 | Nov 23 | Nov 26 | Nov 29 | Dec 2 | Dec 5 | Dec 10 | Dec 16 |
Freeze probabilities 1991–2020 at Crystal Lake 4NW, 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 60098 →Compare Woodstock with another place →
Compared with the next station
The nearest other station, Marengo, IL, 9 miles southwest of Woodstock, has a last frost 3 days later (April 28), a first frost 10 days earlier (October 12), a season 13 days shorter.
When it snows in Woodstock, Illinois
The first measurable snow (0.1 inch or more) in Woodstock usually arrives around November 22, and the last of the season around April 8. Those are the middle dates across the winters of 1991–2020 at Crystal Lake 4NW, IL, 4.4 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 17 days after the last snow.
Planting calendar for 60098
| When | What to do |
|---|---|
| February 14 – February 28 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 28 – March 14 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 28 – April 11 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 25 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 60098 is 4 miles from Crystal Lake 4NW, IL, which stands at 940 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 6 other ZIP codes share the station; its figures are presented in full for 60014 (Crystal Lake). The 2023 USDA Plant Hardiness Zone Map lists ZIP 60098 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°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.