USDA Hardiness Zone 6b
Frost Dates for 62859 — Mc Leansboro, Illinois
NOAA 1991–2020 normals from Mcleansboro, IL (446 ft), under a mile southwest.
Updated
In Mc Leansboro, the last spring frost (32°F) is around April 11 in half of years and has passed by April 26 in nine years out of ten. The first fall frost comes around October 21, as early as October 6 one year in ten, leaving a typical freeze-free season of 190 days (NOAA, Mcleansboro, IL).
- Last spring frost
- April 11
- First fall frost
- October 21
- Growing season
- 190 days
- Hardiness zone
- 6b
50% probability
50% probability
freeze-free, 50%
-5 to 0°F (-20.6 to -17.8°C) coldest night
- First snow
- December 16
- Last snow
- February 20
- Winters with snow
- 100%
- Snow per year
- 11.7"
median, 1991–2020
median, 1991–2020
20 of 20 observed
NOAA normal
Frost risk by date in Mc Leansboro
Half of springs at Mcleansboro, IL see their last 32°F night by April 11; only one in ten is past it by March 27, and one in ten still has one after April 26. Planting tender crops after April 18 leaves a 30% risk of a frost on them, after April 22 20%, and after April 26 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 21 in half of years, as early as October 6 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 9 days later, around October 30; in spring the one-in-ten date for 28°F is April 17, 9 days before the 32°F one. The freeze-free season lasts 190 days in a typical year, longer than at 66% of the 158 Illinois stations; it reaches 211 days one year in ten and falls short of 169 one year in ten. On average 110 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 22, and return around October 11. Severe cold of 16°F or below comes every winter, usually between November 30 and March 3.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 6 | Apr 11 | Apr 15 | Apr 19 | Apr 22 | Apr 25 | Apr 29 | May 2 | May 8 |
| 32°F | Mar 27 | Mar 31 | Apr 4 | Apr 8 | Apr 11 | Apr 14 | Apr 18 | Apr 22 | Apr 26 |
| 28°F | Mar 16 | Mar 21 | Mar 26 | Mar 30 | Apr 1 | Apr 4 | Apr 7 | Apr 12 | Apr 17 |
| 24°F | Mar 6 | Mar 11 | Mar 15 | Mar 18 | Mar 22 | Mar 25 | Mar 29 | Apr 1 | Apr 7 |
| 20°F | Feb 25 | Mar 2 | Mar 5 | Mar 8 | Mar 12 | Mar 15 | Mar 18 | Mar 23 | Mar 29 |
| 16°F | Feb 12 | Feb 20 | Feb 26 | Mar 1 | Mar 3 | Mar 6 | Mar 9 | Mar 14 | Mar 19 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 28 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 13 | Oct 16 | Oct 20 | Oct 23 |
| 32°F | Oct 6 | Oct 12 | Oct 15 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 28 | Nov 1 |
| 28°F | Oct 17 | Oct 22 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 10 |
| 24°F | Oct 26 | Oct 31 | Nov 2 | Nov 5 | Nov 7 | Nov 10 | Nov 14 | Nov 18 | Nov 23 |
| 20°F | Nov 4 | Nov 8 | Nov 11 | Nov 15 | Nov 18 | Nov 22 | Nov 26 | Dec 1 | Dec 7 |
| 16°F | Nov 11 | Nov 16 | Nov 21 | Nov 25 | Nov 30 | Dec 3 | Dec 7 | Dec 15 | Dec 21 |
Freeze probabilities 1991–2020 at Mcleansboro, 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 62859 →Compare Mc Leansboro with another place →
Weather by month in Mc Leansboro
July is the warmest month at Mcleansboro, IL, averaging 89°F by day and 66°F at night; January is the coldest at 41°F and 22°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 79% of years.
Warmth for growing adds up to 4,039 growing degree days a year (base 50°F), more than at 85% of the 158 Illinois stations. 37% of them (1,511) have built up by the end of June, and July adds the most, 854. Precipitation totals 47.2 inches a year, most in April (5.3") and least in August (2.6"); May to September bring 42% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 41 | 22 | 3.6 | 100% | 26 | 7 |
| Feb | 46 | 24 | 2.9 | 100% | 21 | 8 |
| Mar | 56 | 34 | 4.5 | 100% | 17 | 70 |
| Apr | 68 | 44 | 5.3 | 79% | 5 | 215 |
| May | 77 | 55 | 4.9 | 4% | <1 | 491 |
| Jun | 85 | 63 | 5.1 | 0% | 0 | 720 |
| Jul | 89 | 66 | 3.5 | 0% | 0 | 854 |
| Aug | 88 | 63 | 2.6 | 0% | 0 | 792 |
| Sep | 82 | 55 | 3.5 | 3% | <1 | 560 |
| Oct | 70 | 43 | 3.4 | 89% | 4 | 252 |
| Nov | 56 | 33 | 4.4 | 100% | 15 | 60 |
| Dec | 45 | 26 | 3.5 | 100% | 23 | 11 |
Monthly normals 1991–2020 at Mcleansboro, IL (446 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, Carmi 3, IL, 19 miles east of Mc Leansboro, has a last frost 4 days later (April 15), a first frost 2 days earlier (October 19), a season 7 days shorter.
When it snows in Mc Leansboro, Illinois
The first measurable snow (0.1 inch or more) in Mc Leansboro usually arrives around December 16, and the last of the season around February 20. Those are the middle dates across the winters of 1991–2020 at Carmi 3, IL, 19.3 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 50 days after the last snow.
Planting calendar for 62859
| When | What to do |
|---|---|
| January 31 – February 14 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 14 – February 28 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 14 – March 28 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 11 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 29 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 7 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 21 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 62859 is under a mile from Mcleansboro, IL, which stands at 446 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 62859 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°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.