USDA Hardiness Zone 7a
Frost Dates for 62926 — Dongola, Illinois
NOAA 1991–2020 normals from Anna 2 NNE, IL (640 ft), 9 miles northwest.
Updated
In Dongola, the last spring frost (32°F) is around April 8 in half of years and has passed by April 26 in nine years out of ten. The first fall frost comes around October 29, as early as October 17 one year in ten, leaving a typical freeze-free season of 203 days (NOAA, Anna 2 NNE, IL).
- Last spring frost
- April 8
- First fall frost
- October 29
- Growing season
- 203 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
- December 19
- Last snow
- February 23
- Winters with snow
- 100%
- Snow per year
- 10.4"
median, 1991–2020
median, 1991–2020
20 of 20 observed
NOAA normal
Frost risk by date in Dongola
Half of springs at Anna 2 NNE, IL see their last 32°F night by April 8; only one in ten is past it by March 22, and one in ten still has one after April 26. Planting tender crops after April 16 leaves a 30% risk of a frost on them, after April 20 20%, and after April 26 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 92% of the 158 Illinois stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 29 in half of years, as early as October 17 one year in ten, and holds off past November 10 one year in ten. A hard freeze of 28°F follows 10 days later, around November 8; in spring the one-in-ten date for 28°F is April 16, 10 days before the 32°F one. The freeze-free season lasts 203 days in a typical year, longer than at 92% of the 158 Illinois stations; it reaches 225 days one year in ten and falls short of 182 one year in ten. On average 95 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 21, and return around October 19. Severe cold of 16°F or below comes every winter, usually between December 13 and February 21.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 4 | Apr 10 | Apr 15 | Apr 18 | Apr 21 | Apr 24 | Apr 27 | May 1 | May 6 |
| 32°F | Mar 22 | Mar 29 | Mar 31 | Apr 4 | Apr 8 | Apr 12 | Apr 16 | Apr 20 | Apr 26 |
| 28°F | Mar 10 | Mar 17 | Mar 21 | Mar 25 | Mar 29 | Apr 1 | Apr 4 | Apr 8 | Apr 16 |
| 24°F | Feb 25 | Mar 2 | Mar 7 | Mar 11 | Mar 15 | Mar 18 | Mar 23 | Mar 29 | Apr 4 |
| 20°F | Feb 11 | Feb 19 | Feb 25 | Mar 1 | Mar 4 | Mar 8 | Mar 12 | Mar 17 | Mar 24 |
| 16°F | Jan 30 | Feb 4 | Feb 10 | Feb 16 | Feb 21 | Feb 26 | Mar 2 | Mar 6 | Mar 12 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 6 | Oct 11 | Oct 14 | Oct 16 | Oct 19 | Oct 21 | Oct 24 | Oct 27 | Oct 31 |
| 32°F | Oct 17 | Oct 21 | Oct 24 | Oct 27 | Oct 29 | Oct 31 | Nov 2 | Nov 5 | Nov 10 |
| 28°F | Oct 27 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 11 | Nov 14 | Nov 19 | Nov 25 |
| 24°F | Nov 4 | Nov 8 | Nov 12 | Nov 15 | Nov 19 | Nov 24 | Nov 28 | Dec 2 | Dec 7 |
| 20°F | Nov 10 | Nov 16 | Nov 22 | Nov 26 | Dec 1 | Dec 4 | Dec 8 | Dec 13 | Dec 21 |
| 16°F | Nov 23 | Nov 30 | Dec 4 | Dec 8 | Dec 13 | Dec 18 | Dec 23 | Dec 27 | Jan 3 |
Freeze probabilities 1991–2020 at Anna 2 NNE, 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 62926 →Compare Dongola with another place →
Weather by month in Dongola
July is the warmest month at Anna 2 NNE, IL, averaging 90°F by day and 69°F at night; January is the coldest at 45°F and 25°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 69% of years.
Warmth for growing adds up to 4,627 growing degree days a year (base 50°F), more than at 99% of the 158 Illinois stations. 38% of them (1,763) have built up by the end of June, and July adds the most, 905. Precipitation totals 51.1 inches a year, most in May (5.9") and least in August (3.2"); May to September bring 42% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 45 | 25 | 3.5 | 100% | 24 | 14 |
| Feb | 50 | 29 | 3.4 | 100% | 19 | 23 |
| Mar | 61 | 37 | 4.8 | 99% | 13 | 113 |
| Apr | 71 | 46 | 5.6 | 69% | 4 | 293 |
| May | 79 | 56 | 5.9 | 4% | 0 | 544 |
| Jun | 87 | 65 | 5.0 | 0% | 0 | 775 |
| Jul | 90 | 69 | 3.7 | 0% | 0 | 905 |
| Aug | 89 | 67 | 3.2 | 0% | 0 | 874 |
| Sep | 84 | 59 | 3.5 | 0% | <1 | 640 |
| Oct | 73 | 48 | 3.9 | 61% | 2 | 329 |
| Nov | 59 | 37 | 4.5 | 100% | 12 | 91 |
| Dec | 48 | 30 | 4.1 | 100% | 21 | 24 |
Monthly normals 1991–2020 at Anna 2 NNE, IL (640 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, Cairo 3N, IL, 22 miles south of Dongola and 327 feet lower, has a last frost 6 days earlier (April 2), a first frost 2 days later (October 31), a season 8 days longer.
When it snows in Dongola, Illinois
The first measurable snow (0.1 inch or more) in Dongola usually arrives around December 19, and the last of the season around February 23. Those are the middle dates across the winters of 1991–2020 at Anna 2 NNE, IL, 9.1 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 44 days after the last snow.
Planting calendar for 62926
| When | What to do |
|---|---|
| January 28 – February 11 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 11 – February 25 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 11 – March 25 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 8 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 6 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 15 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 29 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 62926 is 9 miles from Anna 2 NNE, IL, which stands at 640 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 62906 (Anna). The 2023 USDA Plant Hardiness Zone Map lists ZIP 62926 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.