Frost dates for 40203Louisville, 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 40203 is matched to the NOAA station Louisville Intl Ap, KY, 8 km away, at 488 ft elevation (25 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 Mcalpine, KY | 440 ft | Mar 31 | Nov 9 |
| Louisville Bowman Fld, KY | 540 ft | Apr 3 | Nov 3 |
| Louisville Wfo, KY | 632 ft | Apr 6 | Nov 1 |
Frost dates near Louisville
- Louisville, KY 40259 · last Mar 31, first Nov 7
- Jeffersonville, IN 47132 · last Apr 3, first Nov 3
- New Albany, IN 47151 · last Mar 31, first Nov 7
- Clarksville, IN 47129 · last Mar 31, first Nov 7
- Masonic Home, KY 40041 · last Apr 3, first Nov 3
- Glenview, KY 40025 · last Apr 3, first Nov 3
- Mount Saint Francis, IN 47146 · 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 40203, 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 40203?
- 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.