Frost dates for 37846Philadelphia, TN
The average last spring frost in Philadelphia is April 5 and the average first fall frost is November 1, giving a typical growing season of about 210 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 5
- Average first fall frost
- Nov 1
- Growing season
- 210 days
Safer after Apr 21 (1-in-10 risk)
Possible by Oct 20 (1-in-10 risk)
Last frost typically in 153 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 3 · Apr 18 · May 5 | Oct 12 · Oct 25 · Nov 5 | 188 days | 100% |
| Frost / freeze (32°F) | Mar 19 · Apr 5 · Apr 21 | Oct 20 · Nov 1 · Nov 15 | 210 days | 100% |
| Hard freeze (28°F) | Mar 6 · Mar 25 · Apr 9 | Oct 31 · Nov 12 · Dec 1 | 233 days | 100% |
Planting calendar for Philadelphia
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 5 – May 11 |
| Tomatoes | Transplant outdoors | Apr 21 – Jul 12 |
| Peppers | Start seeds indoors | Mar 5 – Apr 5 |
| Peppers | Transplant outdoors | May 5 – Jun 5 |
| Eggplant | Start seeds indoors | Mar 22 – Apr 20 |
| Eggplant | Transplant outdoors | May 5 – Jun 5 |
| Cucumbers | Sow outdoors | May 5 – Jul 22 |
| Summer squash | Sow outdoors | Apr 21 – Jun 5 |
| Winter squash & pumpkins | Sow outdoors | May 5 – Jun 5 |
| Snap beans | Sow outdoors | Apr 21 – Aug 14 |
| Sweet corn | Sow outdoors | Apr 21 – Jul 12 |
| Watermelon & cantaloupe | Sow outdoors | May 5 – Jun 5 |
| Okra | Sow outdoors | Apr 28 – May 21 |
| Peas | Sow outdoors (spring) | Mar 5 – Apr 20 |
| Potatoes | Plant outdoors (spring) | Mar 5 – May 5 |
| Onions | Start seeds indoors (spring) | Jan 22 – Feb 18 |
| Onions | Transplant outdoors (spring) | Mar 22 – Apr 20 |
| Broccoli | Start seeds indoors (spring) | Feb 15 – Mar 21 |
| Broccoli | Transplant outdoors (spring) | Mar 22 – Apr 20 |
| Broccoli | Start seeds indoors (fall) | Jul 2 – Jul 12 |
| Broccoli | Transplant outdoors (fall) | Aug 1 – Aug 12 |
| Cabbage | Start seeds indoors (spring) | Feb 5 – Mar 5 |
| Cabbage | Transplant outdoors (spring) | Mar 5 – Apr 5 |
| Cabbage | Start seeds indoors (fall) | Jun 22 – Jul 22 |
| Cabbage | Transplant outdoors (fall) | Jul 22 – Aug 22 |
| Leaf lettuce | Sow outdoors (spring) | Mar 5 – May 21 |
| Leaf lettuce | Sow outdoors (fall) | Jul 22 – Sep 7 |
| Spinach | Sow outdoors (spring) | Feb 26 – Apr 11 |
| Spinach | Sow outdoors (fall) | Aug 8 – Sep 12 |
| Radishes | Sow outdoors (spring) | Mar 5 – Apr 25 |
| Radishes | Sow outdoors (fall) | Jul 22 – Sep 22 |
| Kale | Sow outdoors (spring) | Mar 22 – Apr 11 |
| Kale | Sow outdoors (fall) | Jul 15 – Aug 22 |
| Carrots | Sow outdoors (spring) | Apr 5 – May 21 |
| Carrots | Sow outdoors (fall) | Jun 22 – Aug 7 |
| Garlic | Plant outdoors (fall) | Oct 22 – Nov 22 |
Where these dates come from
ZIP code 37846 is matched to the NOAA station Lenoir City, TN, 19.5 km away, at 785 ft elevation (284 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Lenoir City, TN (used) | 785 ft | Apr 5 | Nov 1 |
| Decatur 7Ne, TN | 750 ft | Apr 10 | Oct 27 |
| Kingston, TN | 814 ft | Apr 3 | Nov 4 |
| Rockwood 2, TN | 767 ft | Apr 8 | Oct 31 |
Frost dates near Philadelphia
- Sweetwater, TN 37874 · last Apr 6, first Oct 31
- Loudon, TN 37774 · last Apr 5, first Nov 1
- Niota, TN 37826 · last Apr 6, first Oct 31
- Ten Mile, TN 37880 · last Apr 10, first Oct 27
- Kingston, TN 37763 · last Apr 3, first Nov 4
- Lenoir City, TN 37771 · last Apr 5, first Nov 1
- Madisonville, TN 37354 · last Apr 13, first Oct 24
- Greenback, TN 37742 · last Apr 5, first Nov 1
Frequently asked questions
- When is the last frost in Philadelphia, TN?
- For ZIP code 37846, the average last spring frost (32°F) is April 5, based on NOAA 1991-2020 climate normals for the Lenoir City, TN weather station. There is a 1-in-10 chance of a frost after April 21.
- When is the first frost in Philadelphia, TN?
- The average first fall frost (32°F) is November 1. There is a 1-in-10 chance of frost by October 20, so tender plants are at risk from that point on.
- How long is the growing season in 37846?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 210 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.