Frost dates for 37924Knoxville, TN
The average last spring frost in Knoxville is April 6 and the average first fall frost is October 29, giving a typical growing season of about 205 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 6
- Average first fall frost
- Oct 29
- Growing season
- 205 days
Safer after Apr 21 (1-in-10 risk)
Possible by Oct 16 (1-in-10 risk)
Last frost typically in 154 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 4 · Apr 19 · May 5 | Oct 9 · Oct 21 · Nov 1 | 184 days | 100% |
| Frost / freeze (32°F) | Mar 23 · Apr 6 · Apr 21 | Oct 16 · Oct 29 · Nov 11 | 205 days | 100% |
| Hard freeze (28°F) | Mar 8 · Mar 27 · Apr 9 | Oct 25 · Nov 7 · Nov 24 | 225 days | 100% |
Planting calendar for Knoxville
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 6 – May 12 |
| Tomatoes | Transplant outdoors | Apr 22 – Jul 9 |
| Peppers | Start seeds indoors | Mar 6 – Apr 6 |
| Peppers | Transplant outdoors | May 6 – Jun 6 |
| Eggplant | Start seeds indoors | Mar 23 – Apr 21 |
| Eggplant | Transplant outdoors | May 6 – Jun 6 |
| Cucumbers | Sow outdoors | May 6 – Jul 19 |
| Summer squash | Sow outdoors | Apr 22 – Jun 6 |
| Winter squash & pumpkins | Sow outdoors | May 6 – Jun 6 |
| Snap beans | Sow outdoors | Apr 22 – Aug 11 |
| Sweet corn | Sow outdoors | Apr 22 – Jul 9 |
| Watermelon & cantaloupe | Sow outdoors | May 6 – Jun 6 |
| Okra | Sow outdoors | Apr 29 – May 22 |
| Peas | Sow outdoors (spring) | Mar 6 – Apr 21 |
| Potatoes | Plant outdoors (spring) | Mar 6 – May 6 |
| Onions | Start seeds indoors (spring) | Jan 23 – Feb 19 |
| Onions | Transplant outdoors (spring) | Mar 23 – Apr 21 |
| Broccoli | Start seeds indoors (spring) | Feb 16 – Mar 22 |
| Broccoli | Transplant outdoors (spring) | Mar 23 – Apr 21 |
| Broccoli | Start seeds indoors (fall) | Jun 29 – Jul 9 |
| Broccoli | Transplant outdoors (fall) | Jul 29 – Aug 9 |
| Cabbage | Start seeds indoors (spring) | Feb 6 – Mar 6 |
| Cabbage | Transplant outdoors (spring) | Mar 6 – Apr 6 |
| Cabbage | Start seeds indoors (fall) | Jun 19 – Jul 19 |
| Cabbage | Transplant outdoors (fall) | Jul 19 – Aug 19 |
| Leaf lettuce | Sow outdoors (spring) | Mar 6 – May 22 |
| Leaf lettuce | Sow outdoors (fall) | Jul 19 – Sep 4 |
| Spinach | Sow outdoors (spring) | Feb 27 – Apr 12 |
| Spinach | Sow outdoors (fall) | Aug 5 – Sep 9 |
| Radishes | Sow outdoors (spring) | Mar 6 – Apr 26 |
| Radishes | Sow outdoors (fall) | Jul 19 – Sep 19 |
| Kale | Sow outdoors (spring) | Mar 23 – Apr 12 |
| Kale | Sow outdoors (fall) | Jul 12 – Aug 19 |
| Carrots | Sow outdoors (spring) | Apr 6 – May 22 |
| Carrots | Sow outdoors (fall) | Jun 19 – Aug 4 |
| Garlic | Plant outdoors (fall) | Oct 19 – Nov 19 |
Where these dates come from
ZIP code 37924 is matched to the NOAA station Sevierville, TN, 21.6 km away, at 899 ft elevation (62 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Sevierville, TN (used) | 899 ft | Apr 6 | Oct 29 |
| Knoxville Exp Stn, TN | 830 ft | Apr 11 | Oct 28 |
| Knoxville Mcghee Tyson Ap, TN | 962 ft | Apr 1 | Nov 2 |
| Norris, TN | 1,110 ft | Apr 22 | Oct 25 |
Frost dates near Knoxville
- Knoxville, TN 37914 · last Apr 11, first Oct 28
- Mascot, TN 37806 · last Apr 24, first Oct 17
- Corryton, TN 37721 · last Apr 22, first Oct 25
- Strawberry Plains, TN 37871 · last Apr 6, first Oct 29
- Blaine, TN 37709 · last Apr 24, first Oct 17
- Kodak, TN 37764 · last Apr 6, first Oct 29
- Seymour, TN 37865 · last Apr 6, first Oct 29
- Luttrell, TN 37779 · last Apr 22, first Oct 25
Frequently asked questions
- When is the last frost in Knoxville, TN?
- For ZIP code 37924, the average last spring frost (32°F) is April 6, based on NOAA 1991-2020 climate normals for the Sevierville, TN weather station. There is a 1-in-10 chance of a frost after April 21.
- When is the first frost in Knoxville, TN?
- The average first fall frost (32°F) is October 29. There is a 1-in-10 chance of frost by October 16, so tender plants are at risk from that point on.
- How long is the growing season in 37924?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 205 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.