When to plant in Philadelphia, PA
Planting dates worked out from Philadelphia's own frost records, not a generic zone chart.
Safe to plant out
Apr 10
1 year in 10 has a later frost
Average last frost
Mar 31
about a 50% chance of a later one
Average first fall frost
Nov 23
1 year in 10 by Nov 6
Frost-free days
231
median, 1991–2020
Station used: Phila Franklin Inst · 1.0 km away · station 18 m, town 12 m. How we match towns to stations
This season
Plan your garden.
Planting dates for common crops
| Crop | Start indoors | Plant out or sow | Harvest from |
|---|---|---|---|
| Tomato | Feb 13 – Feb 27 | Apr 10 – Apr 24 | Jun 4 |
| Sweet pepper | Jan 30 – Feb 13 | Apr 10 – Apr 24 | Jun 9 |
| Lettuce (leaf) | Feb 1 – Feb 8 | Mar 8 – Mar 22 | Apr 17 |
| Peas | — | Mar 8 – Apr 5 | May 2 |
| Bush beans | — | Apr 4 – Apr 25 | May 24 |
| Carrot | — | Mar 20 – May 1 | May 19 |
| Beet | — | Mar 20 – May 1 | May 9 |
| Potato | — | Mar 20 – Apr 10 | May 29 |
| Kale | Feb 1 – Feb 15 | Mar 15 – Mar 29 | Apr 27 |
| Broccoli | Jan 25 – Feb 8 | Mar 8 – Mar 29 | May 7 |
| Cucumber | Mar 13 – Mar 20 | Apr 10 – Apr 24 | May 30 |
| Summer squash and zucchini | Mar 13 – Mar 20 | Apr 10 – Apr 24 | May 25 |
| Winter squash | Mar 13 – Mar 20 | Apr 10 – Apr 24 | Jun 29 |
| Sweet corn | — | Apr 4 – Apr 25 | Jun 3 |
| Onion (from sets) | — | Mar 8 – Mar 29 | Jun 6 |
| Garlic | — | Oct 29 – Nov 26 (fall) | following summer |
| Spinach | — | Mar 8 – Apr 5 | Apr 15 |
| Basil | Feb 27 – Mar 13 | Apr 10 – Apr 24 | Jun 6 |
Philadelphia's weather over time
How the growing season has shifted here, year by year, from the station's own records.
Each year's last spring frostLong-term trend
See the data as a table
| Year | Last spring frost |
|---|---|
| 1994 | Mar 17 |
| 1995 | Apr 6 |
| 1996 | Apr 9 |
| 1997 | Apr 10 |
| 1998 | Mar 22 |
| 1999 | Mar 26 |
| 2000 | Apr 9 |
| 2002 | Mar 23 |
| 2003 | Mar 14 |
| 2004 | Apr 5 |
| 2005 | Mar 15 |
| 2006 | Mar 21 |
| 2007 | Apr 9 |
| 2008 | Mar 29 |
| 2009 | Mar 23 |
| 2010 | Mar 27 |
| 2011 | Mar 29 |
| 2012 | Mar 27 |
| 2013 | Apr 4 |
| 2014 | Mar 28 |
| 2015 | Apr 26 |
| 2016 | Apr 11 |
| 2017 | Mar 24 |
| 2018 | Apr 10 |
| 2019 | Apr 1 |
| 2021 | Apr 4 |
| 2022 | Mar 30 |
| 2023 | Mar 20 |
| 2024 | Mar 24 |
| 2025 | Apr 9 |
| 2026 | Apr 9 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1995 | 212 |
| 1996 | 215 |
| 1997 | 219 |
| 1998 | 274 |
| 1999 | 235 |
| 2000 | 224 |
| 2002 | 248 |
| 2003 | 262 |
| 2004 | 222 |
| 2005 | 252 |
| 2006 | 227 |
| 2007 | 227 |
| 2008 | 209 |
| 2009 | 257 |
| 2010 | 246 |
| 2011 | 255 |
| 2012 | 253 |
| 2013 | 222 |
| 2014 | 231 |
| 2015 | 237 |
| 2016 | 241 |
| 2018 | 214 |
| 2019 | 221 |
| 2021 | 233 |
| 2022 | 232 |
| 2023 | 249 |
| 2024 | 250 |
| 2025 | 215 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1994 | 21.7 °C |
| 1995 | 21.4 °C |
| 1996 | 20.5 °C |
| 1997 | 21.0 °C |
| 1998 | 22.6 °C |
| 1999 | 22.2 °C |
| 2000 | 20.6 °C |
| 2002 | 22.9 °C |
| 2003 | 21.4 °C |
| 2004 | 22.2 °C |
| 2005 | 23.3 °C |
| 2006 | 22.4 °C |
| 2007 | 20.9 °C |
| 2008 | 21.9 °C |
| 2009 | 20.9 °C |
| 2010 | 23.2 °C |
| 2011 | 22.5 °C |
| 2012 | 22.2 °C |
| 2013 | 21.4 °C |
| 2014 | 21.3 °C |
| 2015 | 22.6 °C |
| 2016 | 22.0 °C |
| 2017 | 21.8 °C |
| 2018 | 22.5 °C |
| 2019 | 22.8 °C |
| 2021 | 22.3 °C |
| 2022 | 22.5 °C |
| 2023 | 21.9 °C |
| 2024 | 22.7 °C |
| 2025 | 22.3 °C |
What this means for you: Since 1994, Philadelphia's last spring frost has come about 2 days later per decade, on average. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Phila Franklin Inst (NOAA GHCN-Daily). Years with too many missing days are left out.