Frost dates for Lancaster Ap, Pennsylvania
Half of years have their last spring frost by April 18 — but 1 year in 10 still frosts after May 5.
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
- May 5
- 1 year in 5
- April 30
- 3 years in 10
- April 25
- 2 years in 5
- April 22
- Half of years (the median)
- April 18
First fall freeze
- Freeze this early in 1 year in 10
- October 10
- 1 year in 5
- October 15
- 3 years in 10
- October 19
- 2 years in 5
- October 22
- Half of years (the median)
- October 25
- Growing season
- about 186 days
- Hardiness zone nearby
- 7a
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, station Lancaster Ap (USW00054737), at 40.12, -76.29. 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
17016, 17026, 17039, 17042, 17046, 17064, 17067, 17073, 17083, 17087, 17088, 17309, 17317, 17366, 17368, 17501, 17505, 17508, 17512, 17516, 17517, 17520, 17522, 17529, 17538, 17540, 17543, 17545, 17551, 17552, 17554, 17560, 17562, 17565, 17572, 17576, 17578, 17579, 17582, 17584, 17601, 17602, 17603, 17606, 19544, 19550, 19551, 19567.
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.
- Hopewell Morgantown, PA — last frost by April 16
- Middletown Harrisburg Intl Ap, PA — last frost by April 9
- Conowingo Dam, MD — last frost by April 3
- Millers 4 Ne, MD — last frost by April 19
- Newark Ag Farm Hcn, DE — last frost by April 7
- Carlisle Wtp, PA — last frost by April 23
Other stations in Pennsylvania.
- Mahanoy City 2 N, PA — last frost by April 30
- Selinsgrove 2 S Hcn, PA — last frost by April 25
- Lehighton 1Ssw, PA — last frost by April 21
- Philadelphia Intl Ap, PA — last frost by April 2
- Willow Grove Nas, PA — last frost by April 11
- Shippensburg, PA — last frost by April 19
- Mt Pocono Mountains Ap, PA — last frost by May 6
- Wilkes-Barre Intl Ap, PA — last frost by April 23