Frost dates for Philadelphia Intl Ap, Pennsylvania
Half of years have their last spring frost by April 2 — but 1 year in 10 still frosts after April 13.
Every other site gives you one date. A frost date is not a date: it is a percentile from 30 years of records at a nearby weather station, and planting to the median means losing the crop in half of years. Both numbers are below, so you can choose the risk yourself.
The odds
Last spring frost
- Frost this late in 1 year in 10
- April 13
- 1 year in 5
- April 8
- 3 years in 10
- April 6
- 2 years in 5
- April 3
- Half of years (the median)
- April 2
First fall freeze
- Freeze this early in 1 year in 10
- October 30
- 1 year in 5
- November 2
- 3 years in 10
- November 5
- 2 years in 5
- November 8
- Half of years (the median)
- November 10
- Growing season
- about 224 days
- Hardiness zones nearby
- 7a, 7b, 8a
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, station Philadelphia Intl Ap (USW00013739), at 39.87, -75.23. These are that station's own records, unshifted. The further your garden is from it, the less exactly they describe your ground — the planner resolves the nearest station to your own ZIP and lowers its confidence with distance, rather than presenting one number as if it were measured in your yard.
Cold air also pools in low ground on the clear, still nights when frost happens, so a hollow can freeze while a slope a hundred metres away does not. No table can know that about your garden. Your own logged frosts eventually can.
ZIP codes nearest this station
08002, 08007, 08012, 08014, 08020, 08027, 08028, 08029, 08030, 08031, 08033, 08034, 08035, 08039, 08045, 08049, 08051, 08052, 08056, 08059, 08061, 08062, 08063, 08065, 08066, 08067, 08071, 08074, 08077, 08078, 08080, 08083, 08084, 08085, 08086, 08090, 08093, 08096, 08097, 08098, 08102, 08103, 08104, 08105, 08106, 08107, 08108, 08109, 08110, 08312, 08343, 19003, 19004, 19008, 19010, 19013, 19014, 19015, 19017, 19018, 19022, 19023, 19026, 19029, 19032, 19033, 19036, 19041, 19043, 19050, 19060, 19061, 19063, 19064, 19066, 19070, 19072, 19073, 19074, 19076, 19078, 19079, 19081, 19082, 19083, 19085, 19086, 19087, 19094, 19096, 19102, 19103, 19104, 19106, 19107, 19109, 19112, 19113, 19121, 19122, 19123, 19125, 19127, 19129, 19130, 19131, 19132, 19133, 19134, 19137, 19139, 19140, 19142, 19143, 19144, 19145, 19146, 19147, 19148, 19151 and 11 more.
What can I plant here, and when? →
Nearby stations
The nearest stations, and how their last-frost dates compare — the frost gradient across your area, which no single station shows.
- Willow Grove Nas, PA — last frost by April 11
- Indian Mills 2 W Hcn, NJ — last frost by April 28
- Newark Ag Farm Hcn, DE — last frost by April 7
- Millville Muni Ap, NJ — last frost by April 24
- Trenton State College, NJ — last frost by April 17
- Hopewell Morgantown, PA — last frost by April 16
Other stations in Pennsylvania.
- Lancaster Ap, PA — last frost by April 18
- Lehighton 1Ssw, PA — last frost by April 21
- Mahanoy City 2 N, PA — last frost by April 30
- Middletown Harrisburg Intl Ap, PA — last frost by April 9
- Mt Pocono Mountains Ap, PA — last frost by May 6
- Wilkes-Barre Intl Ap, PA — last frost by April 23
- Carlisle Wtp, PA — last frost by April 23
- Selinsgrove 2 S Hcn, PA — last frost by April 25