Frost dates for Mckeesport, Pennsylvania
Half of years have their last spring frost by May 2, but 1 year in 10 still frosts after May 20.
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 20
- 1 year in 5
- May 14
- 3 years in 10
- May 10
- 2 years in 5
- May 5
- Half of years (the median)
- May 2
First fall freeze
How often the first freeze comes on or before each date.
- 1 year in 10
- October 1
- 1 year in 5
- October 6
- 3 years in 10
- October 11
- 2 years in 5
- October 15
- Half of years (the median)
- October 20
- Growing season
- about 170 days
- Hardiness zone nearby
- 6b
- Summer days
- a usual high of about 28 °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 ~4 °C38 °F · low ~-6 °C20 °F · rain ~77 mm3 in
- February
- high ~5 °C42 °F · low ~-6 °C22 °F · rain ~64 mm2.5 in
- March
- high ~10 °C51 °F · low ~-2 °C29 °F · rain ~81 mm3.2 in
- April
- high ~18 °C64 °F · low ~3 °C38 °F · rain ~96 mm3.8 in
- May
- high ~23 °C74 °F · low ~9 °C47 °F · rain ~101 mm4 in
- June
- high ~27 °C81 °F · low ~14 °C57 °F · rain ~127 mm5 in
- July
- high ~29 °C85 °F · low ~16 °C61 °F · rain ~105 mm4.1 in
- August
- high ~29 °C83 °F · low ~16 °C60 °F · rain ~90 mm3.5 in
- September
- high ~25 °C77 °F · low ~12 °C53 °F · rain ~88 mm3.4 in
- October
- high ~18 °C65 °F · low ~5 °C42 °F · rain ~81 mm3.2 in
- November
- high ~12 °C53 °F · low ~0 °C32 °F · rain ~76 mm3 in
- December
- high ~6 °C42 °F · low ~-4 °C25 °F · rain ~90 mm3.6 in
Where these numbers come from
NOAA NCEI 1991–2020 Climate Normals, the Mckeesport station (listed by NOAA as Mckeesport, USC00365573), at 40.34, -79.86. 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
15018, 15028, 15037, 15045, 15047, 15083, 15088, 15131, 15132, 15133, 15135, 15637, 15678.
Nearby stations
The nearest stations and how their last-frost dates compare. Together they show how frost varies across your area.
- Charleroi Lock, PA, last frost by April 13
- Washington 3 NE, PA, last frost by April 24
- Schenley Lock, PA, last frost by April 21
- Beaver Falls 1 NE, PA, last frost by April 27
- Lake Lynn, WV, last frost by April 25
- Confluence 1 SW Dam, PA, last frost by April 30
Other stations in Pennsylvania.
- Putneyville 2 SE Dam, PA, last frost by May 10
- Johnstown Cambria County Airport, PA, last frost by April 29
- Mercer, PA, last frost by May 15
- Prince Gallitzin State Park, PA, last frost by May 10
- Franklin, PA, last frost by May 2
- Altoona Blair County Airport, PA, last frost by April 23
- Philipsburg 2 S, PA, last frost by May 13
- State College, PA, last frost by April 20
When do I plant? · Where the dates come from
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