Frost dates for Johnstown Cambria County Airport, Pennsylvania
Half of years have their last spring frost by April 29, but 1 year in 10 still frosts after May 17.
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 17
- 1 year in 5
- May 10
- 3 years in 10
- May 5
- 2 years in 5
- May 1
- Half of years (the median)
- April 29
First fall freeze
How often the first freeze comes on or before each date.
- 1 year in 10
- October 5
- 1 year in 5
- October 10
- 3 years in 10
- October 14
- 2 years in 5
- October 18
- Half of years (the median)
- October 21
- Growing season
- about 176 days
- Hardiness zones nearby
- 6a, 6b
- Summer days
- a usual high of about 25 °C77 °F
- Lettuce and spinach run to seed
- July to August, 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 ~1 °C33 °F · low ~-7 °C19 °F · rain ~64 mm2.5 in
- February
- high ~2 °C36 °F · low ~-6 °C21 °F · rain ~64 mm2.5 in
- March
- high ~7 °C45 °F · low ~-2 °C28 °F · rain ~79 mm3.1 in
- April
- high ~14 °C58 °F · low ~4 °C38 °F · rain ~90 mm3.5 in
- May
- high ~20 °C68 °F · low ~9 °C49 °F · rain ~105 mm4.1 in
- June
- high ~24 °C75 °F · low ~14 °C57 °F · rain ~112 mm4.4 in
- July
- high ~26 °C79 °F · low ~16 °C61 °F · rain ~107 mm4.2 in
- August
- high ~25 °C77 °F · low ~16 °C60 °F · rain ~100 mm3.9 in
- September
- high ~21 °C71 °F · low ~12 °C53 °F · rain ~101 mm4 in
- October
- high ~15 °C59 °F · low ~6 °C43 °F · rain ~78 mm3.1 in
- November
- high ~9 °C47 °F · low ~0 °C33 °F · rain ~79 mm3.1 in
- December
- high ~3 °C38 °F · low ~-4 °C25 °F · rain ~68 mm2.7 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the Johnstown Cambria County Airport station (listed by NOAA as Johnstown Cambria Co Ap, USW00004726), at 40.32, -78.83. 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
15563, 15901, 15902, 15904, 15905, 15906, 15909, 15921, 15928, 15930, 15934, 15935…
+12 moreShow fewer
15936, 15937, 15942, 15944, 15945, 15951, 15952, 15953, 15954, 15955, 15956, 15963.
Nearby stations
The nearest stations and how their last-frost dates compare. Together they show how frost varies across your area.
- Altoona Blair County Airport, PA, last frost by April 23
- Prince Gallitzin State Park, PA, last frost by May 10
- Confluence 1 SW Dam, PA, last frost by April 30
- Cumberland 2, MD, last frost by April 15
- Putneyville 2 SE Dam, PA, last frost by May 10
- Philipsburg 2 S, PA, last frost by May 13
Other stations in Pennsylvania.
- Schenley Lock, PA, last frost by April 21
- Mckeesport, PA, last frost by May 2
- Charleroi Lock, PA, last frost by April 13
- State College, PA, last frost by April 20
- Shippensburg, PA, last frost by April 19
- Washington 3 NE, PA, last frost by April 24
- Beaver Falls 1 NE, PA, last frost by April 27
- Carlisle Wtp, PA, last frost by April 23
When do I plant? · Where the dates come from
More ways Milpa can help
When do I plant? · What grows well together? · Plan my garden · What can I plant now? · Something wrong in the garden? · Keep a garden diary · Heard a tip?