USDA Hardiness Zone 7a
Frost Dates for 42420 — Henderson, Kentucky
NOAA 1991–2020 normals from Henderson State Police, KY (420 ft), 2 miles south.
Updated
In Henderson, the last spring frost (32°F) is around April 9 in half of years and has passed by April 24 in nine years out of ten. The first fall frost comes around October 26, as early as October 12 one year in ten, leaving a typical freeze-free season of 198 days (NOAA, Henderson State Police, KY).
- Last spring frost
- April 9
- First fall frost
- October 26
- Growing season
- 198 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
- Rare
- Last snow
- Rare
- Winters with snow
- 20%
- Snow per year
- 0.6"
median, 1991–2020
median, 1991–2020
4 of 20 observed
NOAA normal
Frost risk by date in Henderson
Half of springs at Henderson State Police, KY see their last 32°F night by April 9; only one in ten is past it by March 26, and one in ten still has one after April 24. Planting tender crops after April 16 leaves a 30% risk of a frost on them, after April 19 20%, and after April 24 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 85% of the 113 Kentucky stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 26 in half of years, as early as October 12 one year in ten, and holds off past November 6 one year in ten. A hard freeze of 28°F follows 9 days later, around November 4; in spring the one-in-ten date for 28°F is April 15, 9 days before the 32°F one. The freeze-free season lasts 198 days in a typical year, longer than at 61% of the 113 Kentucky stations; it reaches 217 days one year in ten and falls short of 179 one year in ten. On average 93 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 20, and return around October 16. Severe cold of 16°F or below comes every winter, usually between December 12 and February 23.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 6 | Apr 10 | Apr 14 | Apr 17 | Apr 20 | Apr 23 | Apr 25 | Apr 30 | May 3 |
| 32°F | Mar 26 | Mar 31 | Apr 3 | Apr 6 | Apr 9 | Apr 12 | Apr 16 | Apr 19 | Apr 24 |
| 28°F | Mar 11 | Mar 18 | Mar 23 | Mar 27 | Mar 31 | Apr 2 | Apr 6 | Apr 10 | Apr 15 |
| 24°F | Feb 27 | Mar 4 | Mar 9 | Mar 13 | Mar 17 | Mar 21 | Mar 25 | Mar 31 | Apr 5 |
| 20°F | Feb 13 | Feb 21 | Feb 26 | Mar 1 | Mar 4 | Mar 8 | Mar 13 | Mar 18 | Mar 27 |
| 16°F | Jan 31 | Feb 6 | Feb 13 | Feb 19 | Feb 23 | Feb 27 | Mar 2 | Mar 6 | Mar 13 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 3 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 18 | Oct 21 | Oct 24 | Oct 28 |
| 32°F | Oct 12 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 28 | Oct 31 | Nov 2 | Nov 6 |
| 28°F | Oct 21 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 6 | Nov 10 | Nov 14 | Nov 20 |
| 24°F | Nov 1 | Nov 5 | Nov 9 | Nov 13 | Nov 16 | Nov 19 | Nov 23 | Nov 29 | Dec 4 |
| 20°F | Nov 9 | Nov 14 | Nov 19 | Nov 24 | Nov 27 | Dec 1 | Dec 6 | Dec 12 | Dec 22 |
| 16°F | Nov 18 | Nov 26 | Dec 1 | Dec 6 | Dec 12 | Dec 19 | Dec 25 | Dec 30 | Jan 7 |
Freeze probabilities 1991–2020 at Henderson State Police, KY, 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 42420 →Compare Henderson with another place →
Compared with the next station
The nearest other station, Henderson 8 SSW, KY, 7 miles southwest of Henderson, has a last frost 5 days earlier (April 4), a first frost 3 days later (October 29), a season 9 days longer.
When it snows in Henderson, Kentucky
Measurable snow is rare here: only 4 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Henderson State Police, KY, 2.3 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 42420
| When | What to do |
|---|---|
| January 29 – February 12 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 12 – February 26 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 12 – March 26 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 9 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 3 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 12 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 26 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 42420 is 2 miles from Henderson State Police, KY, which stands at 420 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 42420 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.