West Middlesex, PA 16159 Frost Dates
Frost dates for West Middlesex, PA, ZIP 16159
Around 05/15 is the usual last spring frost, about 260 days away. The first fall frost typically arrives around 10/03, about 140 frost-free days later.
West Middlesex sits in USDA Zone 6a (-10 to -5°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 6a around West Middlesex has about 5 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
The actual range around West Middlesex's last frost
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 06/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How West Middlesex compares
About 140 days separate West Middlesex's last and first frost, putting it 37,089 of 40,283 ZIP codes nationally. Within PA, it ranks 1,999 of 2,088.
Learn more
local microclimates explains what one yard in West Middlesex can differ from the 16159 normal, and zone vs. frost date explains why Zone 6a and West Middlesex's frost date answer different questions.