Frost dates for 40231Louisville, KY
The average last spring frost in Louisville is March 31 and the average first fall frost is November 7, giving a typical growing season of about 222 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 31
- Average first fall frost
- Nov 7
- Growing season
- 222 days
Safer after Apr 16 (1-in-10 risk)
Possible by Oct 28 (1-in-10 risk)
First frost typically in 4 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) | Mar 29 · Apr 11 · Apr 28 | Oct 16 · Oct 29 · Nov 9 | 199 days | 100% |
| Frost / freeze (32°F) | Mar 14 · Mar 31 · Apr 16 | Oct 28 · Nov 7 · Nov 23 | 222 days | 100% |
| Hard freeze (28°F) | Mar 1 · Mar 20 · Apr 3 | Nov 4 · Nov 17 · Dec 4 | 244 days | 100% |
Planting calendar for Louisville
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 | Feb 28 – May 6 |
| Tomatoes | Transplant outdoors | Apr 16 – Jul 18 |
| Peppers | Start seeds indoors | Feb 28 – Mar 31 |
| Peppers | Transplant outdoors | Apr 30 – May 31 |
| Eggplant | Start seeds indoors | Mar 17 – Apr 15 |
| Eggplant | Transplant outdoors | Apr 30 – May 31 |
| Cucumbers | Sow outdoors | Apr 30 – Jul 28 |
| Summer squash | Sow outdoors | Apr 16 – May 31 |
| Winter squash & pumpkins | Sow outdoors | Apr 30 – May 31 |
| Snap beans | Sow outdoors | Apr 16 – Aug 20 |
| Sweet corn | Sow outdoors | Apr 16 – Jul 18 |
| Watermelon & cantaloupe | Sow outdoors | Apr 30 – May 31 |
| Okra | Sow outdoors | Apr 23 – May 16 |
| Peas | Sow outdoors (spring) | Feb 28 – Apr 15 |
| Potatoes | Plant outdoors (spring) | Feb 28 – Apr 30 |
| Onions | Start seeds indoors (spring) | Jan 17 – Feb 13 |
| Onions | Transplant outdoors (spring) | Mar 17 – Apr 15 |
| Broccoli | Start seeds indoors (spring) | Feb 10 – Mar 16 |
| Broccoli | Transplant outdoors (spring) | Mar 17 – Apr 15 |
| Broccoli | Start seeds indoors (fall) | Jul 8 – Jul 18 |
| Broccoli | Transplant outdoors (fall) | Aug 7 – Aug 18 |
| Cabbage | Start seeds indoors (spring) | Jan 31 – Feb 28 |
| Cabbage | Transplant outdoors (spring) | Feb 28 – Mar 31 |
| Cabbage | Start seeds indoors (fall) | Jun 28 – Jul 28 |
| Cabbage | Transplant outdoors (fall) | Jul 28 – Aug 28 |
| Leaf lettuce | Sow outdoors (spring) | Feb 28 – May 16 |
| Leaf lettuce | Sow outdoors (fall) | Jul 28 – Sep 13 |
| Spinach | Sow outdoors (spring) | Feb 21 – Apr 6 |
| Spinach | Sow outdoors (fall) | Aug 14 – Sep 18 |
| Radishes | Sow outdoors (spring) | Feb 28 – Apr 20 |
| Radishes | Sow outdoors (fall) | Jul 28 – Sep 28 |
| Kale | Sow outdoors (spring) | Mar 17 – Apr 6 |
| Kale | Sow outdoors (fall) | Jul 21 – Aug 28 |
| Carrots | Sow outdoors (spring) | Mar 31 – May 16 |
| Carrots | Sow outdoors (fall) | Jun 28 – Aug 13 |
| Garlic | Plant outdoors (fall) | Oct 28 – Nov 28 |
Where these dates come from
ZIP code 40231 is matched to the NOAA station Louisville Intl Ap, KY, 5.5 km away, at 488 ft elevation (9 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Louisville Intl Ap, KY (used) | 488 ft | Mar 31 | Nov 7 |
| Louisville Bowman Fld, KY | 540 ft | Apr 3 | Nov 3 |
| Louisville Wfo, KY | 632 ft | Apr 6 | Nov 1 |
| Louisville Mcalpine, KY | 440 ft | Mar 31 | Nov 9 |
Frost dates near Louisville
- Louisville, KY 40201 · last Mar 31, first Nov 7
- Masonic Home, KY 40041 · last Apr 3, first Nov 3
- Fairdale, KY 40118 · last Mar 31, first Nov 7
- Jeffersonville, IN 47132 · last Apr 3, first Nov 3
- Hillview, KY 40129 · last Apr 6, first Nov 1
- Glenview, KY 40025 · last Apr 3, first Nov 3
- Clarksville, IN 47129 · last Mar 31, first Nov 7
- Harrods Creek, KY 40027 · last Apr 3, first Nov 3
Frequently asked questions
- When is the last frost in Louisville, KY?
- For ZIP code 40231, the average last spring frost (32°F) is March 31, based on NOAA 1991-2020 climate normals for the Louisville Intl Ap, KY weather station. There is a 1-in-10 chance of a frost after April 16.
- When is the first frost in Louisville, KY?
- The average first fall frost (32°F) is November 7. There is a 1-in-10 chance of frost by October 28, so tender plants are at risk from that point on.
- How long is the growing season in 40231?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 222 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.