Frost dates for Carlisle Wtp, Pennsylvania
Half of years have their last spring frost by April 23, but 1 year in 10 still frosts after May 9.
A frost date is really a percentile from 30 years of records at a nearby weather station: in about half of years a frost still comes after the median date. Both numbers are below, so you can choose the risk yourself.
The odds
Last spring frost
How often a frost still comes on or after each date.
- 1 year in 10
- May 9
- 1 year in 5
- May 3
- 3 years in 10
- April 30
- 2 years in 5
- April 26
- Half of years (the median)
- April 23
First fall freeze
How often the first freeze comes on or before each date.
- 1 year in 10
- October 4
- 1 year in 5
- October 8
- 3 years in 10
- October 11
- 2 years in 5
- October 15
- Half of years (the median)
- October 18
- Growing season
- about 177 days
- Hardiness zone nearby
- 7a
- Summer days
- a usual high of about 29 °C83 °F
- Lettuce and spinach run to seed
- June to September, in hot, long days (how we know)
Summer and rain
A growing garden needs about 25 mm1 in of water a week, rain and watering together. Here is what a normal month brings.
Month by month
- January
- high ~3 °C38 °F · low ~-6 °C20 °F · rain ~78 mm3.1 in
- February
- high ~5 °C41 °F · low ~-6 °C22 °F · rain ~66 mm2.6 in
- March
- high ~10 °C50 °F · low ~-2 °C29 °F · rain ~103 mm4.1 in
- April
- high ~17 °C63 °F · low ~4 °C38 °F · rain ~96 mm3.8 in
- May
- high ~22 °C72 °F · low ~9 °C49 °F · rain ~120 mm4.7 in
- June
- high ~27 °C81 °F · low ~15 °C58 °F · rain ~112 mm4.4 in
- July
- high ~30 °C85 °F · low ~17 °C62 °F · rain ~138 mm5.4 in
- August
- high ~29 °C84 °F · low ~16 °C61 °F · rain ~102 mm4 in
- September
- high ~25 °C77 °F · low ~12 °C53 °F · rain ~126 mm5 in
- October
- high ~19 °C66 °F · low ~5 °C42 °F · rain ~108 mm4.3 in
- November
- high ~12 °C53 °F · low ~0 °C32 °F · rain ~80 mm3.1 in
- December
- high ~6 °C42 °F · low ~-4 °C25 °F · rain ~91 mm3.6 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the Carlisle Wtp station (listed by NOAA as Carlisle Wtp, USC00361920), at 40.23, -77.19. These are that station’s own records, unshifted. The further your garden is from it, the less exactly they describe your ground. The planner finds the nearest station to your garden and lowers its confidence with distance, so no number is presented as if it were measured in your garden.
Cold air also pools in low ground on the clear, still nights when frost happens, so a hollow can freeze while a slope a few hundred feet away does not. No table can know that about your garden. A few seasons of your own logged frosts can.
ZIP codes nearest this station
17007, 17013, 17015, 17020, 17024, 17040, 17050, 17053, 17065, 17068, 17072, 17074…
+3 moreShow fewer
17081, 17090, 17324.
Nearby stations
The nearest stations and how their last-frost dates compare. Together they show how frost varies across your area.
- Shippensburg, PA, last frost by April 19
- Middletown Harrisburg International Airport, PA, last frost by April 9
- Millers 4 NE, MD, last frost by April 19
- Selinsgrove 2 S, PA, last frost by April 25
- Hagerstown Washington County Airport, MD, last frost by April 7
- Lancaster Airport, PA, last frost by April 18
Other stations in Pennsylvania.
- State College, PA, last frost by April 20
- Altoona Blair County Airport, PA, last frost by April 23
- Mahanoy City 2 N, PA, last frost by April 30
- Philipsburg 2 S, PA, last frost by May 13
- Prince Gallitzin State Park, PA, last frost by May 10
- Rodale Rsch Center, PA, last frost by April 26
- Johnstown Cambria County Airport, PA, last frost by April 29
- Lehighton 1 SSW, PA, last frost by April 21
When do I plant? · Where the dates come from
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