Boston, IN frost dates
Last spring frostApr 24median date
First fall frostOct 20median date
Growing season179 daysfrost-free
Hardiness zone6aZone 6a
How Boston compares
- In 8 years out of 10, the last spring frost in Boston falls between April 8 and May 10, a 32-day window. The first fall frost falls between October 7 and November 1.
- The median last frost is 2 days later than the Indiana median of Apr 22.
- Its 179-day growing season is longer than 39% of the 733 Indiana places with a regular frost season (state median 182 days).
- The last frost is 5 days earlier than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 117 nights a year at or below 32°F.
- Compared with Hamilton, OH, 45 km away, the last frost here is 2 days later than there and the growing season is the same length.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 8 |
| 50% (median) | April 24 |
| 10% (safe for tender plants) | May 10 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 7 |
| 50% (median) | October 20 |
| 90% (late) | November 1 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Boston, IN
Boston, IN frost dates — last frost Apr 24, first frost Oct 20, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Jan 30 to Feb 13Transplant outside: Mar 27 to Apr 10
Start indoors: Feb 13 to Feb 27Transplant outside: May 8 to May 22
Start indoors: Feb 13 to Feb 27Transplant outside: May 8 to May 22
Start indoors: Feb 27 to Mar 13Transplant outside: May 1 to May 15
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 3 to Apr 17Sow outdoors: Mar 27 to May 1Plant for fall: Aug 25 to Sep 22
Start indoors: Feb 27 to Mar 13Transplant outside: Mar 27 to Apr 10Sow outdoors: Mar 27 to Apr 10Plant for fall: Aug 11 to Sep 1
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 10 to Apr 24Plant for fall: Jul 14 to Aug 4
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 3 to Apr 17Plant for fall: Jul 14 to Aug 4
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 10 to Apr 24Plant for fall: Jul 14 to Aug 4
Start indoors: Mar 13 to Mar 27Transplant outside: May 15 to May 29Sow outdoors: May 15 to May 29
Start indoors: Mar 13 to Mar 27Transplant outside: May 1 to May 15
Sow outdoors: Mar 13 to Apr 3Plant for fall: Jul 28 to Aug 18
Sow outdoors: Mar 13 to Apr 3Plant for fall: Aug 25 to Sep 15
Sow outdoors: Mar 20 to May 1Plant for fall: Sep 8 to Sep 29
Start indoors: Mar 27 to Apr 3Transplant outside: May 8 to May 15Sow outdoors: May 1 to May 15Plant for fall: Aug 4 to Aug 18
Start indoors: Mar 27 to Apr 3Sow outdoors: May 1 to May 15Plant for fall: Aug 11 to Aug 25
Start indoors: Mar 27 to Apr 3Sow outdoors: May 1 to May 15
Start indoors: Mar 27 to Apr 3Transplant outside: May 8 to May 22
Sow outdoors: Apr 3 to May 1Plant for fall: Jul 28 to Aug 11
Sow outdoors: Apr 3 to May 1Plant for fall: Aug 11 to Aug 25
Sow outdoors: Apr 3 to Apr 24
Sow outdoors: Apr 10 to May 8Plant for fall: Aug 11 to Aug 25
Sow outdoors: Apr 10 to May 1Plant for fall: Aug 25 to Sep 15
Sow outdoors: May 1 to May 22Plant for fall: Aug 4 to Aug 18
Sow outdoors: May 1 to May 15
Transplant outside: May 8 to May 29
Plant for fall: Oct 6 to Nov 10
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Boston, IN
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 30 – Feb 13 | Mar 27 – Apr 10 | — | — |
| Peppers | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Eggplant | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Tomatoes | Feb 27 – Mar 13 | May 1 – May 15 | — | — |
| Lettuce | Feb 27 – Mar 13 | Apr 3 – Apr 17 | Mar 27 – May 1 | Aug 25 – Sep 22 |
| Kale | Feb 27 – Mar 13 | Mar 27 – Apr 10 | Mar 27 – Apr 10 | Aug 11 – Sep 1 |
| Broccoli | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 14 – Aug 4 |
| Cabbage | Feb 27 – Mar 13 | Apr 3 – Apr 17 | — | Jul 14 – Aug 4 |
| Cauliflower | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 14 – Aug 4 |
| Okra | Mar 13 – Mar 27 | May 15 – May 29 | May 15 – May 29 | — |
| Basil | Mar 13 – Mar 27 | May 1 – May 15 | — | — |
| Peas | — | — | Mar 13 – Apr 3 | Jul 28 – Aug 18 |
| Spinach | — | — | Mar 13 – Apr 3 | Aug 25 – Sep 15 |
| Radishes | — | — | Mar 20 – May 1 | Sep 8 – Sep 29 |
| Cucumbers | Mar 27 – Apr 3 | May 8 – May 15 | May 1 – May 15 | Aug 4 – Aug 18 |
| Zucchini & Summer Squash | Mar 27 – Apr 3 | — | May 1 – May 15 | Aug 11 – Aug 25 |
| Winter Squash & Pumpkins | Mar 27 – Apr 3 | — | May 1 – May 15 | — |
| Melons & Watermelon | Mar 27 – Apr 3 | May 8 – May 22 | — | — |
| Carrots | — | — | Apr 3 – May 1 | Jul 28 – Aug 11 |
| Beets | — | — | Apr 3 – May 1 | Aug 11 – Aug 25 |
| Potatoes | — | — | Apr 3 – Apr 24 | — |
| Swiss Chard | — | — | Apr 10 – May 8 | Aug 11 – Aug 25 |
| Cilantro | — | — | Apr 10 – May 1 | Aug 25 – Sep 15 |
| Green Beans | — | — | May 1 – May 22 | Aug 4 – Aug 18 |
| Sweet Corn | — | — | May 1 – May 15 | — |
| Sweet Potatoes | — | May 8 – May 29 | — | — |
| Garlic | — | — | — | Oct 6 – Nov 10 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Richmond Wtr Wks, IN weather station, 13 km away (elevation 1,004 ft (306 m)).
Frost dates near Boston
- Richmond Apr 24 · Oct 20
- Brownsville Apr 24 · Oct 20
- Centerville Apr 24 · Oct 20
- Liberty Apr 20 · Oct 21
- West College Corner Apr 20 · Oct 21
- Webster Apr 24 · Oct 20
- Greens Fork Apr 27 · Oct 9
- Milton Apr 27 · Oct 9
- Fountain City Apr 24 · Oct 20
- Bath Apr 20 · Oct 21
Frequently asked questions
When is the last frost in Boston, IN?
The median last spring frost in Boston, IN is April 24. There is still about a 10% chance of frost after May 10, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Boston, IN?
The median first fall frost is October 20, with about a 10% chance of frost before October 7.
How long is the growing season in Boston, IN?
About 179 days between the median last spring frost and first fall frost.
What planting zone is Boston, IN?
Boston, IN is in USDA hardiness zone 6a.