USDA Hardiness Zone 8a
Frost Dates for 71929 — Bismarck, Arkansas
NOAA 1991–2020 normals from Degray Lake Sp, AR (490 ft), 4 miles southeast.
Updated
In Bismarck, the last spring frost (32°F) is around March 20 in half of years and has passed by April 7 in nine years out of ten. The first fall frost comes around November 10, as early as October 27 one year in ten, leaving a typical freeze-free season of 234 days (NOAA, Degray Lake Sp, AR).
- Last spring frost
- March 20
- First fall frost
- November 10
- Growing season
- 234 days
- Hardiness zone
- 8a
50% probability
50% probability
freeze-free, 50%
10 to 15°F (-12.2 to -9.4°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 48%
- Snow per year
- 2.3"
median, 1991–2020
median, 1991–2020
11 of 23 observed
NOAA normal
Frost risk by date in Bismarck
Half of springs at Degray Lake Sp, AR see their last 32°F night by March 20; only one in ten is past it by February 28, and one in ten still has one after April 7. Planting tender crops after March 29 leaves a 30% risk of a frost on them, after April 3 20%, and after April 7 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 60% of the 105 Arkansas stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 10 in half of years, as early as October 27 one year in ten, and holds off past November 28 one year in ten. A hard freeze of 28°F follows 13 days later, around November 23; in spring the one-in-ten date for 28°F is March 25, 13 days before the 32°F one. The freeze-free season lasts 234 days in a typical year, longer than at 73% of the 105 Arkansas stations; it reaches 260 days one year in ten and falls short of 208 one year in ten. On average 58 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 15 days longer, to about April 4, and return around October 30. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 65%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 15 | Mar 24 | Mar 29 | Apr 1 | Apr 4 | Apr 7 | Apr 11 | Apr 16 | Apr 21 |
| 32°F | Feb 28 | Mar 6 | Mar 12 | Mar 16 | Mar 20 | Mar 25 | Mar 29 | Apr 3 | Apr 7 |
| 28°F | Feb 13 | Feb 21 | Feb 26 | Mar 1 | Mar 4 | Mar 8 | Mar 13 | Mar 18 | Mar 25 |
| 24°F | Jan 28 | Feb 2 | Feb 9 | Feb 15 | Feb 20 | Feb 25 | Mar 1 | Mar 5 | Mar 11 |
| 20°F93% of yrs | Jan 7 | Jan 17 | Jan 25 | Jan 30 | Feb 2 | Feb 8 | Feb 15 | Feb 22 | Mar 2 |
| 16°F65% of yrs | Dec 30 | Jan 4 | Jan 11 | Jan 17 | Jan 22 | Jan 29 | Feb 3 | Feb 10 | Feb 19 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 17 | Oct 21 | Oct 25 | Oct 28 | Oct 30 | Nov 1 | Nov 4 | Nov 9 | Nov 15 |
| 32°F | Oct 27 | Nov 1 | Nov 4 | Nov 6 | Nov 10 | Nov 14 | Nov 17 | Nov 22 | Nov 28 |
| 28°F | Nov 4 | Nov 9 | Nov 14 | Nov 19 | Nov 23 | Nov 26 | Dec 1 | Dec 5 | Dec 11 |
| 24°F | Nov 15 | Nov 22 | Nov 27 | Dec 1 | Dec 5 | Dec 10 | Dec 16 | Dec 24 | Jan 1 |
| 20°F93% of yrs | Nov 29 | Dec 6 | Dec 14 | Dec 22 | Dec 28 | Jan 1 | Jan 5 | Jan 12 | Jan 25 |
| 16°F65% of yrs | Dec 11 | Dec 22 | Dec 29 | Jan 1 | Jan 5 | Jan 9 | Jan 15 | Jan 22 | Feb 4 |
Freeze probabilities 1991–2020 at Degray Lake Sp, AR, 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 71929 →Compare Bismarck with another place →
Compared with the next station
The nearest other station, Hot Springs Asos, AR, 8 miles east of Bismarck, has a last frost 4 days later (March 24), a first frost 1 day earlier (November 9), a season 4 days shorter.
When it snows in Bismarck, Arkansas
Measurable snow is rare here: only 11 of 23 winters from 1991 to 2020 recorded 0.1 inch or more at Bonnerdale 5 E, AR, 8.8 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 71929
| When | What to do |
|---|---|
| January 9 – January 23 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| January 23 – February 6 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| February 20 – March 6 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 20 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 18 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 27 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 10 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 71929 is 4 miles from Degray Lake Sp, AR, which stands at 490 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 71929 in zone 8a, the band where the coldest night of the year averaged 10 to 15°F (-12.2 to -9.4°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.