Frost dates for 46278Indianapolis, IN
The average last spring frost in Indianapolis is April 12 and the average first fall frost is October 29, giving a typical growing season of about 198 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 12
- Average first fall frost
- Oct 29
- Growing season
- 198 days
Safer after Apr 29 (1-in-10 risk)
Possible by Oct 16 (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 9 · Apr 23 · May 9 | Oct 7 · Oct 18 · Oct 29 | 177 days | 100% |
| Frost / freeze (32°F) | Mar 30 · Apr 12 · Apr 29 | Oct 16 · Oct 29 · Nov 10 | 198 days | 100% |
| Hard freeze (28°F) | Mar 16 · Apr 1 · Apr 17 | Oct 27 · Nov 6 · Nov 23 | 221 days | 100% |
Planting calendar for Indianapolis
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 12 – May 18 |
| Tomatoes | Transplant outdoors | Apr 28 – Jul 9 |
| Peppers | Start seeds indoors | Mar 12 – Apr 12 |
| Peppers | Transplant outdoors | May 12 – Jun 12 |
| Eggplant | Start seeds indoors | Mar 29 – Apr 27 |
| Eggplant | Transplant outdoors | May 12 – Jun 12 |
| Cucumbers | Sow outdoors | May 12 – Jul 19 |
| Summer squash | Sow outdoors | Apr 28 – Jun 12 |
| Winter squash & pumpkins | Sow outdoors | May 12 – Jun 12 |
| Snap beans | Sow outdoors | Apr 28 – Aug 11 |
| Sweet corn | Sow outdoors | Apr 28 – Jul 9 |
| Watermelon & cantaloupe | Sow outdoors | May 12 – Jun 12 |
| Okra | Sow outdoors | May 5 – May 28 |
| Peas | Sow outdoors (spring) | Mar 12 – Apr 27 |
| Potatoes | Plant outdoors (spring) | Mar 12 – May 12 |
| Onions | Start seeds indoors (spring) | Jan 29 – Feb 25 |
| Onions | Transplant outdoors (spring) | Mar 29 – Apr 27 |
| Broccoli | Start seeds indoors (spring) | Feb 22 – Mar 28 |
| Broccoli | Transplant outdoors (spring) | Mar 29 – Apr 27 |
| Broccoli | Start seeds indoors (fall) | Jun 29 – Jul 9 |
| Broccoli | Transplant outdoors (fall) | Jul 29 – Aug 9 |
| Cabbage | Start seeds indoors (spring) | Feb 12 – Mar 12 |
| Cabbage | Transplant outdoors (spring) | Mar 12 – Apr 12 |
| Cabbage | Start seeds indoors (fall) | Jun 19 – Jul 19 |
| Cabbage | Transplant outdoors (fall) | Jul 19 – Aug 19 |
| Leaf lettuce | Sow outdoors (spring) | Mar 12 – May 28 |
| Leaf lettuce | Sow outdoors (fall) | Jul 19 – Sep 4 |
| Spinach | Sow outdoors (spring) | Mar 5 – Apr 18 |
| Spinach | Sow outdoors (fall) | Aug 5 – Sep 9 |
| Radishes | Sow outdoors (spring) | Mar 12 – May 2 |
| Radishes | Sow outdoors (fall) | Jul 19 – Sep 19 |
| Kale | Sow outdoors (spring) | Mar 29 – Apr 18 |
| Kale | Sow outdoors (fall) | Jul 12 – Aug 19 |
| Carrots | Sow outdoors (spring) | Apr 12 – May 28 |
| Carrots | Sow outdoors (fall) | Jun 19 – Aug 4 |
| Garlic | Plant outdoors (fall) | Oct 19 – Nov 19 |
Where these dates come from
ZIP code 46278 is matched to the NOAA station Indianapolis Eagle Creek Ap, IN, 5.5 km away, at 823 ft elevation (30 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Indianapolis Eagle Creek Ap, IN (used) | 823 ft | Apr 12 | Oct 29 |
| Whitestown, IN | 941 ft | Apr 21 | Oct 20 |
| Indianapolis, IN | 790 ft | Apr 15 | Oct 26 |
| Indianapolis Nwfo, IN | 790 ft | Apr 12 | Oct 27 |
Frost dates near Indianapolis
- Indianapolis, IN 46254 · last Apr 12, first Oct 29
- Zionsville, IN 46077 · last Apr 21, first Oct 20
- Brownsburg, IN 46112 · last Apr 12, first Oct 29
- Whitestown, IN 46075 · last Apr 21, first Oct 20
- Pittsboro, IN 46167 · last Apr 23, first Oct 19
- Avon, IN 46123 · last Apr 12, first Oct 29
- Carmel, IN 46032 · last Apr 21, first Oct 21
- Westfield, IN 46074 · last Apr 21, first Oct 21
Frequently asked questions
- When is the last frost in Indianapolis, IN?
- For ZIP code 46278, the average last spring frost (32°F) is April 12, based on NOAA 1991-2020 climate normals for the Indianapolis Eagle Creek Ap, IN weather station. There is a 1-in-10 chance of a frost after April 29.
- When is the first frost in Indianapolis, IN?
- 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 46278?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 198 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.