Altoona, PA 16603 Frost Dates
Altoona, PA: when does the frost end?
Around 04/23 is the usual last spring frost, about 238 days away. Fall's first freeze usually shows up around 10/21, roughly 177 days after the last spring frost.
Altoona sits in USDA Zone 6b (-5 to 0°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.
Stretching the season past the first frost
With roughly 8 weeks until Altoona's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Altoona's last frost
04/23 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/08 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/11 and only about 1 year in 10 sees frost after that.
Altoona against the rest of the dataset
Altoona's growing season runs about 177 days, ranking 26,012 of 40,283 US ZIP codes measured here, longest to shortest. Within PA, it ranks 943 of 2,088.
Learn more
Before leaning on 16603's figures: zone vs. frost date explains why Zone 6b and Altoona's frost date answer different questions, while the frost range explains how to read the range around Altoona's dates instead of trusting one.