Last spring frost
Apr 5
Frost Dates for Mercer, TN
First fall frost
Oct 29
Growing season
207 days
Hardiness zone
7b
In an average year around Mercer, TN, the last spring frost (32°F) is about Apr 5 and the first fall frost is about Oct 29, giving roughly a 207-day growing season. To be safe most years, wait until Mar 19 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | May 2 | Apr 16 | Mar 31 |
| Freeze (32°F) | Apr 21 | Apr 5 | Mar 19 |
| Hard (28°F) | Apr 10 | Mar 25 | Mar 4 |
| Severe (24°F) | Apr 1 | Mar 11 | Feb 19 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 2 | Apr 27 | Apr 23 | Apr 19 | Apr 16 | Apr 12 | Apr 9 | Apr 5 | Mar 31 |
| 32°F | Apr 21 | Apr 16 | Apr 11 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 26 | Mar 19 |
| 28°F | Apr 10 | Apr 5 | Apr 1 | Mar 30 | Mar 25 | Mar 21 | Mar 16 | Mar 12 | Mar 4 |
| 24°F | Apr 1 | Mar 25 | Mar 18 | Mar 15 | Mar 11 | Mar 7 | Mar 2 | Feb 25 | Feb 19 |
| 20°F | Mar 18 | Mar 11 | Mar 6 | Feb 28 | Feb 25 | Feb 20 | Feb 15 | Feb 8 | Jan 31 |
| 16°F | Mar 7 | Feb 28 | Feb 22 | Feb 15 | Feb 8 | Feb 2 | Jan 30 | Jan 24 | Jan 15 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Oct 7 | Oct 20 | Nov 1 |
| Freeze (32°F) | Oct 16 | Oct 29 | Nov 10 |
| Hard (28°F) | Oct 27 | Nov 7 | Nov 25 |
| Severe (24°F) | Nov 4 | Nov 20 | Dec 7 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 7 | Oct 11 | Oct 15 | Oct 18 | Oct 20 | Oct 23 | Oct 25 | Oct 28 | Nov 1 |
| 32°F | Oct 16 | Oct 21 | Oct 24 | Oct 27 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 10 |
| 28°F | Oct 27 | Nov 1 | Nov 3 | Nov 5 | Nov 7 | Nov 10 | Nov 14 | Nov 19 | Nov 25 |
| 24°F | Nov 4 | Nov 8 | Nov 12 | Nov 16 | Nov 20 | Nov 23 | Nov 27 | Dec 1 | Dec 7 |
| 20°F | Nov 12 | Nov 18 | Nov 24 | Nov 29 | Dec 2 | Dec 7 | Dec 12 | Dec 20 | Dec 28 |
| 16°F | Nov 27 | Dec 4 | Dec 11 | Dec 19 | Dec 25 | Dec 29 | Jan 2 | Jan 8 | Jan 17 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Jackson Mckellar Ap, Tn, about 11.2 miles away@if(!empty($station['elevation_ft'])), at 433 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Mercer, TN?
On average, the last spring frost (32°F) around Mercer, TN is about Apr 5. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 19.
When is the first frost in the fall?
The first fall frost around Mercer, TN typically arrives about Oct 29. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Apr 5 on average, or Mar 19 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 207 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 38392 Planting calendar → Tennessee frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026