USDA Hardiness Zone 7a
Frost Dates for 42223 — Fort Campbell, Kentucky
NOAA 1991–2020 normals from Clarksville Outlaw Airport, TN (560 ft), 3 miles southeast.
Updated
In Fort Campbell, the last spring frost (32°F) is around April 6 in half of years and has passed by April 23 in nine years out of ten. The first fall frost comes around October 28, as early as October 15 one year in ten, leaving a typical freeze-free season of 204 days (NOAA, Clarksville Outlaw Airport, TN).
- Last spring frost
- April 6
- First fall frost
- October 28
- Growing season
- 204 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
- 36%
- Snow per year
- 0.5"
median, 1991–2020
median, 1991–2020
8 of 22 observed
NOAA normal
Frost risk by date in Fort Campbell
Half of springs at Clarksville Outlaw Airport, TN see their last 32°F night by April 6; only one in ten is past it by March 20, and one in ten still has one after April 23. Planting tender crops after April 13 leaves a 30% risk of a frost on them, after April 18 20%, and after April 23 10%. The 17 days between the even-odds date and the one-in-ten date is narrower than at 47% of the 113 Kentucky stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 28 in half of years, as early as October 15 one year in ten, and holds off past November 9 one year in ten. A hard freeze of 28°F follows 10 days later, around November 7; in spring the one-in-ten date for 28°F is April 11, 12 days before the 32°F one. The freeze-free season lasts 204 days in a typical year, longer than at 72% of the 113 Kentucky stations; it reaches 226 days one year in ten and falls short of 183 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 12 days longer, to about April 18, and return around October 19. Severe cold of 16°F or below comes in 99% of winters, usually between December 16 and February 15.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 3 | Apr 8 | Apr 12 | Apr 15 | Apr 18 | Apr 21 | Apr 24 | Apr 28 | May 4 |
| 32°F | Mar 20 | Mar 26 | Mar 31 | Apr 3 | Apr 6 | Apr 9 | Apr 13 | Apr 18 | Apr 23 |
| 28°F | Mar 7 | Mar 14 | Mar 18 | Mar 22 | Mar 25 | Mar 29 | Apr 1 | Apr 6 | Apr 11 |
| 24°F | Feb 21 | Feb 28 | Mar 3 | Mar 8 | Mar 13 | Mar 16 | Mar 20 | Mar 25 | Mar 31 |
| 20°F | Feb 5 | Feb 13 | Feb 20 | Feb 25 | Feb 28 | Mar 3 | Mar 8 | Mar 14 | Mar 20 |
| 16°F99% of yrs | Jan 20 | Jan 30 | Feb 4 | Feb 10 | Feb 15 | Feb 20 | Feb 26 | Mar 2 | Mar 11 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 7 | Oct 11 | Oct 14 | Oct 17 | Oct 19 | Oct 22 | Oct 24 | Oct 27 | Oct 31 |
| 32°F | Oct 15 | Oct 20 | Oct 23 | Oct 26 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 9 |
| 28°F | Oct 26 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 9 | Nov 13 | Nov 17 | Nov 24 |
| 24°F | Nov 4 | Nov 8 | Nov 13 | Nov 16 | Nov 18 | Nov 22 | Nov 27 | Dec 1 | Dec 7 |
| 20°F | Nov 13 | Nov 18 | Nov 23 | Nov 27 | Dec 1 | Dec 4 | Dec 9 | Dec 15 | Dec 22 |
| 16°F99% of yrs | Nov 24 | Dec 1 | Dec 5 | Dec 10 | Dec 16 | Dec 23 | Dec 28 | Jan 2 | Jan 11 |
Freeze probabilities 1991–2020 at Clarksville Outlaw Airport, TN, 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 42223 →Compare Fort Campbell with another place →
Weather by month in Fort Campbell
July is the warmest month at Clarksville Outlaw Airport, TN, averaging 89°F by day and 68°F at night; January is the coldest at 46°F and 28°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 66% of years.
Warmth for growing adds up to 4,504 growing degree days a year (base 50°F), more than at 86% of the 113 Kentucky stations. 39% of them (1,737) have built up by the end of June, and July adds the most, 874. Precipitation totals 47.3 inches a year, most in May (4.9") and least in August (2.9"); May to September bring 40% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 46 | 28 | 3.3 | 100% | 22 | 23 |
| Feb | 51 | 31 | 3.9 | 100% | 17 | 36 |
| Mar | 60 | 38 | 4.3 | 98% | 10 | 112 |
| Apr | 70 | 47 | 4.6 | 66% | 2 | 281 |
| May | 78 | 57 | 4.9 | 2% | 0 | 535 |
| Jun | 86 | 64 | 3.7 | 0% | 0 | 750 |
| Jul | 89 | 68 | 3.7 | 0% | 0 | 874 |
| Aug | 89 | 66 | 2.9 | 0% | 0 | 851 |
| Sep | 82 | 59 | 3.5 | 0% | 0 | 617 |
| Oct | 72 | 47 | 4.1 | 64% | 2 | 306 |
| Nov | 59 | 37 | 4.0 | 99% | 11 | 87 |
| Dec | 49 | 31 | 4.4 | 100% | 18 | 31 |
Monthly normals 1991–2020 at Clarksville Outlaw Airport, TN (560 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, Clarksville Wwtp, TN, 10 miles southeast of Fort Campbell and 158 feet lower, has a last frost 3 days earlier (April 3), a first frost 4 days later (November 1), a season 8 days longer.
When it snows in Fort Campbell, Kentucky
Measurable snow is rare here: only 8 of 22 winters from 1991 to 2020 recorded 0.1 inch or more at Clarksville Wwtp, TN, 10.2 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 42223
| When | What to do |
|---|---|
| January 26 – February 9 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 9 – February 23 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 9 – March 23 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 6 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 5 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 14 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 28 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 42223 is 3 miles from Clarksville Outlaw Airport, TN, which stands at 560 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 37042 (Clarksville). The 2023 USDA Plant Hardiness Zone Map lists ZIP 42223 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.