USDA Hardiness Zone 8a
Frost Dates for 38017 — Collierville, Tennessee
NOAA 1991–2020 normals from Collierville, TN (300 ft), 2 miles north.
Updated
In Collierville, the last spring frost (32°F) is around March 29 in half of years and has passed by April 15 in nine years out of ten. The first fall frost comes around November 3, as early as October 22 one year in ten, leaving a typical freeze-free season of 220 days (NOAA, Collierville, TN).
- Last spring frost
- March 29
- First fall frost
- November 3
- Growing season
- 220 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
- January 28
- Last snow
- February 7
- Winters with snow
- 95%
- Snow per year
- 2.1"
median, 1991–2020
median, 1991–2020
19 of 20 observed
NOAA normal
Frost risk by date in Collierville
Half of springs at Collierville, TN see their last 32°F night by March 29; only one in ten is past it by March 9, and one in ten still has one after April 15. Planting tender crops after April 4 leaves a 30% risk of a frost on them, after April 7 20%, and after April 15 10%. The 17 days between the even-odds date and the one-in-ten date is narrower than at 34% of the 144 Tennessee stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 3 in half of years, as early as October 22 one year in ten, and holds off past November 20 one year in ten. A hard freeze of 28°F follows 11 days later, around November 14; in spring the one-in-ten date for 28°F is April 3, 12 days before the 32°F one. The freeze-free season lasts 220 days in a typical year, longer than at 90% of the 144 Tennessee stations; it reaches 246 days one year in ten and falls short of 197 one year in ten. On average 75 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 9, and return around October 25. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 88%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 24 | Mar 30 | Apr 4 | Apr 6 | Apr 9 | Apr 12 | Apr 16 | Apr 20 | Apr 26 |
| 32°F | Mar 9 | Mar 15 | Mar 21 | Mar 24 | Mar 29 | Apr 1 | Apr 4 | Apr 7 | Apr 15 |
| 28°F | Feb 24 | Mar 1 | Mar 6 | Mar 9 | Mar 13 | Mar 16 | Mar 21 | Mar 27 | Apr 3 |
| 24°F | Feb 6 | Feb 16 | Feb 23 | Feb 27 | Mar 1 | Mar 5 | Mar 8 | Mar 13 | Mar 19 |
| 20°F98% of yrs | Jan 19 | Jan 31 | Feb 4 | Feb 12 | Feb 18 | Feb 24 | Feb 28 | Mar 4 | Mar 11 |
| 16°F88% of yrs | Jan 4 | Jan 14 | Jan 24 | Jan 30 | Feb 2 | Feb 8 | Feb 15 | Feb 23 | Mar 1 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 12 | Oct 17 | Oct 20 | Oct 22 | Oct 25 | Oct 28 | Oct 30 | Nov 2 | Nov 6 |
| 32°F | Oct 22 | Oct 26 | Oct 30 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 13 | Nov 20 |
| 28°F | Oct 31 | Nov 3 | Nov 6 | Nov 10 | Nov 14 | Nov 17 | Nov 22 | Nov 28 | Dec 4 |
| 24°F | Nov 7 | Nov 13 | Nov 17 | Nov 23 | Nov 29 | Dec 2 | Dec 6 | Dec 14 | Dec 24 |
| 20°F98% of yrs | Nov 17 | Nov 28 | Dec 4 | Dec 10 | Dec 18 | Dec 25 | Dec 31 | Jan 4 | Jan 14 |
| 16°F88% of yrs | Dec 5 | Dec 15 | Dec 25 | Dec 30 | Jan 2 | Jan 6 | Jan 12 | Jan 20 | Feb 1 |
Freeze probabilities 1991–2020 at Collierville, 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 38017 →Compare Collierville with another place →
Frost risk through the year in Collierville
In Collierville, the spring curve drops under 10% on April 15 and the fall curve passes 10% on October 22, 190 days later; that gap is longer than at 90% of the 144 Tennessee stations with frost dates. The spring risk falls from 90% to 10% over 37 days (March 9 to April 15) and the fall risk climbs from 10% to 90% over 29 days (October 22 to November 20): the last frost moves more from year to year than the first. At Germantown 4SE, TN, 4 miles west, the same gap runs from April 9 to October 26, 10 days longer.
| Planted on | Another 32°F night | 28°F night |
|---|---|---|
| Mar 15 | 80% | 43% |
| Mar 22 | 67% | 28% |
| Mar 2950% date | 50% | 17% |
| Apr 5 | 27% | under 10% |
| Apr 12 | 14% | under 10% |
| Apr 19 | under 10% | under 10% |
Weather by month in Collierville
July is the warmest month at Collierville, TN, averaging 91°F by day and 70°F at night; January is the coldest at 50°F and 29°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 40% of years.
Warmth for growing adds up to 5,146 growing degree days a year (base 50°F), more than at 94% of the 144 Tennessee stations. 40% of them (2,039) have built up by the end of June, and July adds the most, 956. Precipitation totals 57.0 inches a year, most in May (5.8") and least in August (3.4"); May to September bring 39% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 50 | 29 | 4.4 | 100% | 22 | 32 |
| Feb | 55 | 32 | 5.0 | 100% | 15 | 50 |
| Mar | 64 | 40 | 5.6 | 94% | 8 | 161 |
| Apr | 73 | 49 | 5.7 | 40% | 1 | 348 |
| May | 82 | 59 | 5.8 | 0% | 0 | 626 |
| Jun | 88 | 67 | 4.2 | 0% | 0 | 823 |
| Jul | 91 | 70 | 4.9 | 0% | 0 | 956 |
| Aug | 91 | 68 | 3.4 | 0% | 0 | 914 |
| Sep | 85 | 61 | 3.7 | 0% | 0 | 685 |
| Oct | 75 | 49 | 4.2 | 38% | 1 | 380 |
| Nov | 63 | 39 | 4.3 | 95% | 10 | 126 |
| Dec | 54 | 33 | 5.8 | 100% | 19 | 46 |
Monthly normals 1991–2020 at Collierville, TN (300 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, Germantown 4SE, TN, 4 miles west of Collierville, has a last frost 7 days earlier (March 22), a first frost 4 days later (November 7), a season 10 days longer.
When it snows in Collierville, Tennessee
The first measurable snow (0.1 inch or more) in Collierville usually arrives around January 28, and the last of the season around February 7. Those are the middle dates across the winters of 1991–2020 at Germantown 4SE, TN, 4.1 miles away: half of years saw snow earlier, half later. Snow fell in 95% of those winters. The last 32°F night of spring typically comes 50 days after the last snow.
Planting calendar for 38017
| When | What to do |
|---|---|
| January 18 – February 1 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 1 – February 15 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 1 – March 15 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 29 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 11 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 20 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 3 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 38017 is 2 miles from Collierville, TN, which stands at 300 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 38017 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.
Frost dates across Tennessee →
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.