USDA Hardiness Zone 7a
Frost Dates for 62938 — Golconda, Illinois
NOAA 1991–2020 normals from Dixon Springs Agric Ctr, IL (527 ft), 9 miles northwest.
Updated
In Golconda, the last spring frost (32°F) is around April 14 in half of years and has passed by April 30 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 189 days (NOAA, Dixon Springs Agric Ctr, IL).
- Last spring frost
- April 14
- First fall frost
- October 21
- Growing season
- 189 days
- Hardiness zone
- 7a
50% probability
50% probability
freeze-free, 50%
0 to 5°F (-17.8 to -15.0°C) coldest night
- First snow
- January 6
- Last snow
- February 2
- Winters with snow
- 72%
- Snow per year
- 7.2"
median, 1991–2020
median, 1991–2020
13 of 18 observed
NOAA normal
Frost risk by date in Golconda
Half of springs at Dixon Springs Agric Ctr, IL see their last 32°F night by April 14; only one in ten is past it by March 28, and one in ten still has one after April 30. Planting tender crops after April 20 leaves a 30% risk of a frost on them, after April 24 20%, and after April 30 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 21 in half of years, as early as October 6 one year in ten, and holds off past November 2 one year in ten. A hard freeze of 28°F follows 10 days later, around October 31; in spring the one-in-ten date for 28°F is April 19, 11 days before the 32°F one. The freeze-free season lasts 189 days in a typical year, longer than at 62% of the 158 Illinois stations; it reaches 208 days one year in ten and falls short of 169 one year in ten. On average 80 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 April 24, and return around October 11. Severe cold of 16°F or below comes every winter, usually between December 3 and February 26.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 10 | Apr 15 | Apr 18 | Apr 21 | Apr 24 | Apr 28 | May 1 | May 5 | May 10 |
| 32°F | Mar 28 | Apr 3 | Apr 7 | Apr 11 | Apr 14 | Apr 17 | Apr 20 | Apr 24 | Apr 30 |
| 28°F | Mar 14 | Mar 22 | Mar 27 | Mar 31 | Apr 2 | Apr 5 | Apr 9 | Apr 13 | Apr 19 |
| 24°F | Feb 28 | Mar 7 | Mar 12 | Mar 16 | Mar 20 | Mar 25 | Mar 30 | Apr 2 | Apr 7 |
| 20°F | Feb 18 | Feb 24 | Feb 28 | Mar 3 | Mar 7 | Mar 11 | Mar 15 | Mar 20 | Mar 27 |
| 16°F | Feb 2 | Feb 10 | Feb 17 | Feb 22 | Feb 26 | Mar 1 | Mar 5 | Mar 10 | Mar 16 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 29 | Oct 3 | Oct 6 | Oct 9 | Oct 11 | Oct 15 | Oct 18 | Oct 20 | Oct 24 |
| 32°F | Oct 6 | Oct 12 | Oct 16 | Oct 19 | Oct 21 | Oct 23 | Oct 26 | Oct 29 | Nov 2 |
| 28°F | Oct 16 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 15 |
| 24°F | Oct 27 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 14 | Nov 18 | Nov 22 | Nov 28 |
| 20°F | Nov 7 | Nov 12 | Nov 16 | Nov 19 | Nov 23 | Nov 26 | Nov 30 | Dec 4 | Dec 10 |
| 16°F | Nov 14 | Nov 22 | Nov 26 | Nov 30 | Dec 3 | Dec 8 | Dec 12 | Dec 19 | Dec 27 |
Freeze probabilities 1991–2020 at Dixon Springs Agric Ctr, 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 62938 →Compare Golconda with another place →
Weather by month in Golconda
July is the warmest month at Dixon Springs Agric Ctr, IL, averaging 88°F by day and 67°F at night; January is the coldest at 43°F and 26°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 84% of years.
Warmth for growing adds up to 4,288 growing degree days a year (base 50°F), more than at 96% of the 158 Illinois stations. 38% of them (1,637) have built up by the end of June, and July adds the most, 849. Precipitation totals 50.6 inches a year, most in May (5.2") and least in February (3.6"); May to September bring 42% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 43 | 26 | 3.8 | 100% | 21 | 12 |
| Feb | 49 | 29 | 3.6 | 100% | 16 | 25 |
| Mar | 59 | 37 | 4.7 | 99% | 10 | 100 |
| Apr | 70 | 46 | 5.0 | 84% | 2 | 271 |
| May | 77 | 56 | 5.2 | 9% | 0 | 509 |
| Jun | 85 | 63 | 4.1 | 0% | 0 | 721 |
| Jul | 88 | 67 | 4.4 | 0% | 0 | 849 |
| Aug | 87 | 65 | 3.7 | 0% | 0 | 809 |
| Sep | 82 | 58 | 3.8 | 3% | 0 | 593 |
| Oct | 71 | 46 | 3.8 | 86% | 2 | 297 |
| Nov | 57 | 37 | 4.3 | 100% | 10 | 85 |
| Dec | 46 | 29 | 4.2 | 100% | 18 | 18 |
Monthly normals 1991–2020 at Dixon Springs Agric Ctr, IL (527 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, Smithland L&D, IL, 15 miles south of Golconda and 170 feet lower, has a last frost 11 days earlier (April 3), a first frost 9 days later (October 30), a season 18 days longer.
When it snows in Golconda, Illinois
The first measurable snow (0.1 inch or more) in Golconda usually arrives around January 6, and the last of the season around February 2. Those are the middle dates across the winters of 1991–2020 at Dixon Springs Agric Ctr, IL, 9 miles away: half of years saw snow earlier, half later. Snow fell in 72% of those winters. The last 32°F night of spring typically comes 71 days after the last snow.
Planting calendar for 62938
| When | What to do |
|---|---|
| February 3 – February 17 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 17 – March 3 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 17 – March 31 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 14 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 62938 is 9 miles from Dixon Springs Agric Ctr, IL, which stands at 527 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 62995 (Vienna). The 2023 USDA Plant Hardiness Zone Map lists ZIP 62938 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°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.