Jefferson, PA frost dates
Last spring frostMay 3median date
First fall frostOct 15median date
Growing season165 daysfrost-free
Hardiness zone6bZone 6b
How Jefferson compares
- In 8 years out of 10, the last spring frost in Jefferson falls between April 19 and May 21, a 32-day window. The first fall frost falls between October 2 and October 28.
- The median last frost is 6 days later than the Pennsylvania median of Apr 27.
- Its 165-day growing season is longer than 30% of the 1,787 Pennsylvania places with a regular frost season (state median 175 days).
- The last frost is 11 days later than the zone 6b median of Apr 22. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6b chart.
- The weather station records an average of 138 nights a year at or below 32°F.
- Compared with Pittsburgh, PA, 57 km away, the last frost here is 9 days later than there and the growing season is 21 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 19 |
| 50% (median) | May 3 |
| 10% (safe for tender plants) | May 21 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 2 |
| 50% (median) | October 15 |
| 90% (late) | October 28 |
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 Jefferson, PA
Jefferson, PA frost dates — last frost May 3, first frost Oct 15, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Feb 8 to Feb 22Transplant outside: Apr 5 to Apr 19
Start indoors: Feb 22 to Mar 8Transplant outside: May 17 to May 31
Start indoors: Feb 22 to Mar 8Transplant outside: May 17 to May 31
Start indoors: Mar 8 to Mar 22Transplant outside: May 10 to May 24
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 12 to Apr 26Sow outdoors: Apr 5 to May 10Plant for fall: Aug 20 to Sep 17
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 5 to Apr 19Sow outdoors: Apr 5 to Apr 19Plant for fall: Aug 6 to Aug 27
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 19 to May 3Plant for fall: Jul 9 to Jul 30
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 12 to Apr 26Plant for fall: Jul 9 to Jul 30
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 19 to May 3Plant for fall: Jul 9 to Jul 30
Start indoors: Mar 22 to Apr 5Transplant outside: May 24 to Jun 7Sow outdoors: May 24 to Jun 7
Start indoors: Mar 22 to Apr 5Transplant outside: May 10 to May 24
Sow outdoors: Mar 22 to Apr 12Plant for fall: Jul 23 to Aug 13
Sow outdoors: Mar 22 to Apr 12Plant for fall: Aug 20 to Sep 10
Sow outdoors: Mar 29 to May 10Plant for fall: Sep 3 to Sep 24
Start indoors: Apr 5 to Apr 12Transplant outside: May 17 to May 24Sow outdoors: May 10 to May 24Plant for fall: Jul 30 to Aug 13
Start indoors: Apr 5 to Apr 12Sow outdoors: May 10 to May 24Plant for fall: Aug 6 to Aug 20
Start indoors: Apr 5 to Apr 12Sow outdoors: May 10 to May 24
Start indoors: Apr 5 to Apr 12Transplant outside: May 17 to May 31
Sow outdoors: Apr 12 to May 10Plant for fall: Jul 23 to Aug 6
Sow outdoors: Apr 12 to May 10Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 12 to May 3
Sow outdoors: Apr 19 to May 17Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 19 to May 10Plant for fall: Aug 20 to Sep 10
Sow outdoors: May 10 to May 31Plant for fall: Jul 30 to Aug 13
Sow outdoors: May 10 to May 24
Transplant outside: May 17 to Jun 7
Plant for fall: Oct 1 to Nov 5
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Jefferson, PA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 8 – Feb 22 | Apr 5 – Apr 19 | — | — |
| Peppers | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Eggplant | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Tomatoes | Mar 8 – Mar 22 | May 10 – May 24 | — | — |
| Lettuce | Mar 8 – Mar 22 | Apr 12 – Apr 26 | Apr 5 – May 10 | Aug 20 – Sep 17 |
| Kale | Mar 8 – Mar 22 | Apr 5 – Apr 19 | Apr 5 – Apr 19 | Aug 6 – Aug 27 |
| Broccoli | Mar 8 – Mar 22 | Apr 19 – May 3 | — | Jul 9 – Jul 30 |
| Cabbage | Mar 8 – Mar 22 | Apr 12 – Apr 26 | — | Jul 9 – Jul 30 |
| Cauliflower | Mar 8 – Mar 22 | Apr 19 – May 3 | — | Jul 9 – Jul 30 |
| Okra | Mar 22 – Apr 5 | May 24 – Jun 7 | May 24 – Jun 7 | — |
| Basil | Mar 22 – Apr 5 | May 10 – May 24 | — | — |
| Peas | — | — | Mar 22 – Apr 12 | Jul 23 – Aug 13 |
| Spinach | — | — | Mar 22 – Apr 12 | Aug 20 – Sep 10 |
| Radishes | — | — | Mar 29 – May 10 | Sep 3 – Sep 24 |
| Cucumbers | Apr 5 – Apr 12 | May 17 – May 24 | May 10 – May 24 | Jul 30 – Aug 13 |
| Zucchini & Summer Squash | Apr 5 – Apr 12 | — | May 10 – May 24 | Aug 6 – Aug 20 |
| Winter Squash & Pumpkins | Apr 5 – Apr 12 | — | May 10 – May 24 | — |
| Melons & Watermelon | Apr 5 – Apr 12 | May 17 – May 31 | — | — |
| Carrots | — | — | Apr 12 – May 10 | Jul 23 – Aug 6 |
| Beets | — | — | Apr 12 – May 10 | Aug 6 – Aug 20 |
| Potatoes | — | — | Apr 12 – May 3 | — |
| Swiss Chard | — | — | Apr 19 – May 17 | Aug 6 – Aug 20 |
| Cilantro | — | — | Apr 19 – May 10 | Aug 20 – Sep 10 |
| Green Beans | — | — | May 10 – May 31 | Jul 30 – Aug 13 |
| Sweet Corn | — | — | May 10 – May 24 | — |
| Sweet Potatoes | — | May 17 – Jun 7 | — | — |
| Garlic | — | — | — | Oct 1 – Nov 5 |
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 Waynesburg 1 E, PA weather station, 11 km away (elevation 942 ft (287 m)).
Frost dates near Jefferson
- Mather May 3 · Oct 15
- Clarksville May 3 · Oct 15
- Rices Landing May 3 · Oct 15
- Crucible May 3 · Oct 15
- Millsboro May 3 · Oct 15
- Carmichaels Apr 28 · Oct 21
- Fredericktown Apr 13 · Nov 5
- East Millsboro Apr 13 · Nov 5
- Isabella Apr 28 · Oct 21
- La Belle Apr 13 · Nov 5
Frequently asked questions
When is the last frost in Jefferson, PA?
The median last spring frost in Jefferson, PA is May 3. There is still about a 10% chance of frost after May 21, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Jefferson, PA?
The median first fall frost is October 15, with about a 10% chance of frost before October 2.
How long is the growing season in Jefferson, PA?
About 165 days between the median last spring frost and first fall frost.
What planting zone is Jefferson, PA?
Jefferson, PA is in USDA hardiness zone 6b.