Frost dates for 40242Louisville, KY
The average last spring frost in Louisville is April 3 and the average first fall frost is November 3, giving a typical growing season of about 214 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 3
- Average first fall frost
- Nov 3
- Growing season
- 214 days
Safer after Apr 19 (1-in-10 risk)
Possible by Oct 21 (1-in-10 risk)
First frost typically in 0 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 2 · Apr 16 · May 3 | Oct 12 · Oct 23 · Nov 3 | 189 days | 100% |
| Frost / freeze (32°F) | Mar 18 · Apr 3 · Apr 19 | Oct 21 · Nov 3 · Nov 16 | 214 days | 100% |
| Hard freeze (28°F) | Mar 4 · Mar 22 · Apr 5 | Nov 1 · Nov 13 · Dec 1 | 237 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 | Mar 3 – May 9 |
| Tomatoes | Transplant outdoors | Apr 19 – Jul 14 |
| Peppers | Start seeds indoors | Mar 3 – Apr 3 |
| Peppers | Transplant outdoors | May 3 – Jun 3 |
| Eggplant | Start seeds indoors | Mar 20 – Apr 18 |
| Eggplant | Transplant outdoors | May 3 – Jun 3 |
| Cucumbers | Sow outdoors | May 3 – Jul 24 |
| Summer squash | Sow outdoors | Apr 19 – Jun 3 |
| Winter squash & pumpkins | Sow outdoors | May 3 – Jun 3 |
| Snap beans | Sow outdoors | Apr 19 – Aug 16 |
| Sweet corn | Sow outdoors | Apr 19 – Jul 14 |
| Watermelon & cantaloupe | Sow outdoors | May 3 – Jun 3 |
| Okra | Sow outdoors | Apr 26 – May 19 |
| Peas | Sow outdoors (spring) | Mar 3 – Apr 18 |
| Potatoes | Plant outdoors (spring) | Mar 3 – May 3 |
| Onions | Start seeds indoors (spring) | Jan 20 – Feb 16 |
| Onions | Transplant outdoors (spring) | Mar 20 – Apr 18 |
| Broccoli | Start seeds indoors (spring) | Feb 13 – Mar 19 |
| Broccoli | Transplant outdoors (spring) | Mar 20 – Apr 18 |
| Broccoli | Start seeds indoors (fall) | Jul 4 – Jul 14 |
| Broccoli | Transplant outdoors (fall) | Aug 3 – Aug 14 |
| Cabbage | Start seeds indoors (spring) | Feb 3 – Mar 3 |
| Cabbage | Transplant outdoors (spring) | Mar 3 – Apr 3 |
| Cabbage | Start seeds indoors (fall) | Jun 24 – Jul 24 |
| Cabbage | Transplant outdoors (fall) | Jul 24 – Aug 24 |
| Leaf lettuce | Sow outdoors (spring) | Mar 3 – May 19 |
| Leaf lettuce | Sow outdoors (fall) | Jul 24 – Sep 9 |
| Spinach | Sow outdoors (spring) | Feb 24 – Apr 9 |
| Spinach | Sow outdoors (fall) | Aug 10 – Sep 14 |
| Radishes | Sow outdoors (spring) | Mar 3 – Apr 23 |
| Radishes | Sow outdoors (fall) | Jul 24 – Sep 24 |
| Kale | Sow outdoors (spring) | Mar 20 – Apr 9 |
| Kale | Sow outdoors (fall) | Jul 17 – Aug 24 |
| Carrots | Sow outdoors (spring) | Apr 3 – May 19 |
| Carrots | Sow outdoors (fall) | Jun 24 – Aug 9 |
| Garlic | Plant outdoors (fall) | Oct 24 – Nov 24 |
Where these dates come from
ZIP code 40242 is matched to the NOAA station Louisville Bowman Fld, KY, 8.3 km away, at 540 ft elevation (80 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Louisville Bowman Fld, KY (used) | 540 ft | Apr 3 | Nov 3 |
| Louisville Intl Ap, KY | 488 ft | Mar 31 | Nov 7 |
| Louisville Mcalpine, KY | 440 ft | Mar 31 | Nov 9 |
| Crestwood 4Ne, KY | 780 ft | Apr 12 | Oct 25 |
Frost dates near Louisville
- Louisville, KY 40222 · last Apr 3, first Nov 3
- Glenview, KY 40025 · last Apr 3, first Nov 3
- Masonic Home, KY 40041 · last Apr 3, first Nov 3
- Harrods Creek, KY 40027 · last Apr 3, first Nov 3
- Prospect, KY 40059 · last Apr 3, first Nov 3
- Pewee Valley, KY 40056 · last Apr 12, first Oct 25
- Jeffersonville, IN 47132 · last Apr 3, first Nov 3
- Crestwood, KY 40014 · last Apr 12, first Oct 25
Frequently asked questions
- When is the last frost in Louisville, KY?
- For ZIP code 40242, the average last spring frost (32°F) is April 3, based on NOAA 1991-2020 climate normals for the Louisville Bowman Fld, KY weather station. There is a 1-in-10 chance of a frost after April 19.
- When is the first frost in Louisville, KY?
- The average first fall frost (32°F) is November 3. There is a 1-in-10 chance of frost by October 21, so tender plants are at risk from that point on.
- How long is the growing season in 40242?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 214 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.