Philadelphia, Pennsylvania: planting zone & frost dates

Philadelphia is in USDA plant hardiness zone 7b, where the average coldest winter night reaches 5 to 10°F (-15.0 to -12.2°C). The typical last spring frost is around Apr 4 and the first fall frost around Nov 11.

Hardiness zone7B5 to 10°F

Last spring frostApr 430% chance of frost after

First fall frostNov 1130% chance of frost before

Growing season232 daysmedian frost-free days

Frost dates

Probability	Last spring frost (32°F)	First fall frost (32°F)
Safer (10% risk)	Apr 12	Nov 4
Typical planning date (30% risk)	Apr 4	Nov 11
Median (50%)	Mar 30	Nov 17

How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.

Frost data comes from NOAA station PHILA FRANKLIN INST, PA (USC00366886), 4.1 mi (6.6 km) from the city center and 39 ft lower than the city center (-12 m). Record used for the 1991–2020 normals: 25 years.

Hardiness zone across Philadelphia

All 49 ZIP codes covering Philadelphia are in zone 7b.

ZIP codes in Philadelphia and their zones

ZIP	Zone	Share of city land
19153	7b	5.4%
19128	7b	5.1%
19154	7b	4.8%
19114	7b	4.2%
19116	7b	3.9%
19131	7b	3.9%
19115	7b	3.8%
19124	7b	3.8%
19111	7b	3.6%
19136	7b	3.6%
19145	7b	3.6%
19148	7b	3.2%
19144	7b	2.7%
19134	7b	2.6%
19119	7b	2.5%
19120	7b	2.4%
19104	7b	2.3%
19118	7b	2.3%
19140	7b	2.3%
19143	7b	2.3%
19152	7b	2.1%
19121	7b	1.8%
19137	7b	1.8%
19149	7b	1.8%
19151	7b	1.8%
19135	7b	1.7%
19132	7b	1.6%
19129	7b	1.5%
19112	7b	1.3%
19138	7b	1.3%
19139	7b	1.3%
19141	7b	1.3%
19142	7b	1.3%
19146	7b	1.3%
19150	7b	1.1%
19122	7b	1.0%
19125	7b	1.0%
19133	7b	1.0%
19147	7b	1.0%
19123	7b	0.9%
19126	7b	0.9%
19130	7b	0.9%
19106	7b	0.6%
19103	7b	0.5%
19107	7b	0.4%
19127	7b	0.4%
19102	7b	0.1%
19108	7b	0.0%
19109	7b	0.0%

Vegetable planting calendar for Philadelphia

Dates are counted from the 30%-risk frost dates above (last frost Apr 4, first frost Nov 11). Shift a week later in cold spots or low-lying ground.

Crop	Start indoors	Transplant / plant out	Direct sow	Fall crop sow/plant
Tomato	Feb 7 – Feb 21	Apr 11 – Apr 25	—	—
Pepper	Jan 24 – Feb 7	Apr 18 – May 2	—	—
Lettuce	Feb 21 – Mar 7	Mar 21 – Apr 11	Mar 7 – Apr 18	Sep 2 – Sep 30
Green Beans	—	—	Apr 11 – May 16	Aug 19 – Sep 2
Sweet Corn	—	—	Apr 11 – May 9	—
Zucchini & Summer Squash	Mar 7 – Mar 14	Apr 11 – Apr 25	Apr 11 – May 2	Aug 19 – Sep 2
Cucumber	Mar 7 – Mar 14	Apr 18 – Apr 25	Apr 11 – May 2	Aug 19 – Sep 2
Carrot	—	—	Mar 14 – Apr 18	Aug 19 – Sep 2
Onion	Jan 10 – Jan 24	Mar 7 – Mar 21	—	—
Potato	—	Mar 7 – Mar 28	—	—
Basil	Feb 21 – Mar 7	Apr 18 – May 2	Apr 18 – May 9	—
Spinach	—	—	Feb 21 – Mar 21	Sep 16 – Oct 14
Kale	Feb 7 – Feb 21	Mar 7 – Mar 28	Mar 7 – Mar 28	Sep 2 – Sep 30
Broccoli	Feb 7 – Feb 21	Mar 21 – Apr 11	—	Aug 19 – Sep 2
Peas	—	—	Feb 21 – Mar 14	Sep 2 – Sep 16
Eggplant	Jan 24 – Feb 7	Apr 18 – May 2	—	—
Cabbage	Feb 7 – Feb 21	Mar 7 – Mar 21	—	Aug 19 – Sep 2
Radish	—	—	Feb 28 – Apr 18	Sep 30 – Oct 28
Strawberry	—	Mar 7 – Mar 28	—	—
Beets	—	—	Mar 14 – Apr 25	Sep 2 – Sep 16

Nearby cities in Pennsylvania

Bethlehem — zone 7a, last frost Apr 26, first frost Oct 17
Allentown — zone 7a, last frost Apr 26, first frost Oct 17
Reading — zone 7a, last frost Apr 21, first frost Oct 22
Pittsburgh — zone 6b, last frost Apr 24, first frost Oct 22
Erie — zone 6b, last frost May 2, first frost Oct 30

More: all Pennsylvania cities · other zone 7b cities: New York, NY, Oklahoma City, OK, Nashville, TN, Washington, DC, Baltimore, MD, Albuquerque, NM, Tulsa, OK, Newark, NJ