USDA Hardiness Zone 6a
Frost Dates for 61834 — Danville, Illinois
NOAA 1991–2020 normals from Danville, IL (555 ft), 3 miles southwest.
Updated
In Danville, the last spring frost (32°F) is around April 21 in half of years and has passed by May 7 in nine years out of ten. The first fall frost comes around October 20, as early as October 6 one year in ten, leaving a typical freeze-free season of 181 days (NOAA, Danville, IL).
- Last spring frost
- April 21
- First fall frost
- October 20
- Growing season
- 181 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 13
- Last snow
- February 25
- Winters with snow
- 91%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
21 of 23 observed
NOAA normal
Frost risk by date in Danville
Half of springs at Danville, IL see their last 32°F night by April 21; only one in ten is past it by April 6, and one in ten still has one after May 7. Planting tender crops after April 27 leaves a 30% risk of a frost on them, after May 1 20%, and after May 7 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 20 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 11 days later, around October 31; in spring the one-in-ten date for 28°F is April 24, 13 days before the 32°F one. The freeze-free season lasts 181 days in a typical year, shorter than at 57% of the 158 Illinois stations; it reaches 200 days one year in ten and falls short of 160 one year in ten. On average 112 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 12 days longer, to about May 3, and return around October 10. Severe cold of 16°F or below comes every winter, usually between December 1 and March 8.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 18 | Apr 23 | Apr 27 | Apr 30 | May 3 | May 6 | May 10 | May 15 | May 19 |
| 32°F | Apr 6 | Apr 11 | Apr 14 | Apr 18 | Apr 21 | Apr 24 | Apr 27 | May 1 | May 7 |
| 28°F | Mar 25 | Mar 31 | Apr 2 | Apr 5 | Apr 8 | Apr 11 | Apr 15 | Apr 19 | Apr 24 |
| 24°F | Mar 10 | Mar 16 | Mar 21 | Mar 25 | Mar 28 | Mar 31 | Apr 2 | Apr 6 | Apr 12 |
| 20°F | Feb 27 | Mar 5 | Mar 10 | Mar 14 | Mar 17 | Mar 21 | Mar 25 | Mar 29 | Apr 1 |
| 16°F | Feb 18 | Feb 24 | Feb 28 | Mar 4 | Mar 8 | Mar 11 | Mar 15 | Mar 19 | Mar 24 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 28 | Oct 2 | Oct 5 | Oct 8 | Oct 10 | Oct 13 | Oct 16 | Oct 18 | Oct 22 |
| 32°F | Oct 6 | Oct 11 | Oct 15 | Oct 18 | Oct 20 | Oct 23 | Oct 25 | Oct 29 | Nov 1 |
| 28°F | Oct 17 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 13 |
| 24°F | Oct 29 | Nov 1 | Nov 5 | Nov 7 | Nov 10 | Nov 14 | Nov 18 | Nov 22 | Nov 29 |
| 20°F | Nov 7 | Nov 11 | Nov 15 | Nov 20 | Nov 24 | Nov 27 | Dec 1 | Dec 3 | Dec 10 |
| 16°F | Nov 14 | Nov 20 | Nov 25 | Nov 29 | Dec 1 | Dec 5 | Dec 9 | Dec 14 | Dec 21 |
Freeze probabilities 1991–2020 at Danville, 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 61834 →Compare Danville with another place →
Weather by month in Danville
July is the warmest month at Danville, IL, averaging 85°F by day and 65°F at night; January is the coldest at 35°F and 20°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 22% of years.
Warmth for growing adds up to 3,633 growing degree days a year (base 50°F), more than at 61% of the 158 Illinois stations. 37% of them (1,340) have built up by the end of June, and July adds the most, 778. Precipitation totals 43.2 inches a year, most in June (5.2") and least in February (2.2"); May to September bring 48% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 35 | 20 | 2.5 | 100% | 26 | 2 |
| Feb | 40 | 23 | 2.2 | 100% | 23 | 6 |
| Mar | 52 | 32 | 3.2 | 100% | 17 | 53 |
| Apr | 65 | 42 | 4.5 | 96% | 5 | 181 |
| May | 75 | 52 | 4.6 | 22% | <1 | 432 |
| Jun | 83 | 61 | 5.2 | 0% | 0 | 666 |
| Jul | 85 | 65 | 4.3 | 0% | 0 | 778 |
| Aug | 84 | 63 | 3.3 | 0% | 0 | 727 |
| Sep | 79 | 56 | 3.3 | 3% | <1 | 519 |
| Oct | 67 | 44 | 3.7 | 87% | 3 | 216 |
| Nov | 52 | 34 | 3.7 | 100% | 14 | 46 |
| Dec | 40 | 25 | 2.7 | 100% | 24 | 7 |
Monthly normals 1991–2020 at Danville, IL (555 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, Perrysville 4 WNW, IN, 9 miles southeast of Danville, has a last frost 2 days later (April 23), a first frost 6 days earlier (October 14), a season 10 days shorter.
When it snows in Danville, Illinois
The first measurable snow (0.1 inch or more) in Danville usually arrives around December 13, and the last of the season around February 25. Those are the middle dates across the winters of 1991–2020 at Danville, IL, 3.1 miles away: half of years saw snow earlier, half later. Snow fell in 91% of those winters. The last 32°F night of spring typically comes 55 days after the last snow.
Planting calendar for 61834
| When | What to do |
|---|---|
| February 10 – February 24 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 24 – March 10 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 24 – April 7 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 21 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 28 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 6 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 20 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 61834 is 3 miles from Danville, IL, which stands at 555 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 61832 (Danville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 61834 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.