Pittsburgh, PA Frost Dates: Last Spring and First Fall Frost

The last spring frost in Pittsburgh, PA comes on April 18 in a typical year, and the first fall frost follows on October 28, leaving a frost-free season of 193 days.

Even odds are a coin toss, so plan around the safer edges: one spring in ten still has a freeze on or after May 6, and one fall in ten has its first freeze by October 14. The median season across the 100 cities on these pages is 229 days; Pittsburgh comes up 36 days short of it, 74th on the list.

Behind every date on this page is one weather station, Pittsburgh Allegheny CO AP (NOAA USW00014762), 6.5 miles south-east of Pittsburgh's internal point in the Census Bureau's files and about 1,250 feet up.

Last spring frost in Pittsburgh

Read the table from the top: a freeze on or after May 6 is a one-in-ten spring, after April 18 is a coin toss, and after April 2 is the usual case.

The early and late dates are 34 days apart, about the spread most cities on these pages show.

Pittsburgh's first fall frost, by chance

NOAA's early fall date for Pittsburgh is October 14, its even-odds date is October 28 and its late date is November 10; the first freeze has come by each of them in one, five and nine years out of ten.

The early and late fall dates are only 27 days apart, a narrow band next to most cities here, so the first freeze keeps close to its schedule in Pittsburgh.

Pittsburgh's frost-free season

A little less room than the middle of these pages, so count the days before you choose a variety. Plan on 171 days in a short year, 193 days in a typical one, and as many as 212 days in a long one.

The season lengths come from NOAA's simulated years, not from subtracting one typical date from the other, so the two will not match to the day. A night at or below 32°F happens in 100% of years at this station, so frost is a yearly event here.

Hard freeze dates for Pittsburgh

Hard freezes trail the light ones by 11 days in fall (November 8 against October 28) and by 13 days in spring (April 5 against April 18). The late 28°F spring date, April 21, is the one that still catches blooms and young transplants one year in ten, and the early fall date, October 28, is when a hard freeze has arrived in one fall out of ten.

What this means for planting in Pittsburgh

University of New Hampshire Extension sorts vegetables by how they cope with cold. Cool-season crops go out before the last frost: counting from April 18, cabbage transplants go in on March 21 and lettuce from March 21 to March 28. Tender crops wait until it has passed, with peppers going out on May 2 and beans sown on or after April 18. Peas are the exception to the count: University of New Hampshire Extension says to plant them as soon as the soil thaws, whatever the frost date.

Counting from the late date, May 6, instead of the typical one delays every after-frost crop by 18 days. That is the price of a one-in-ten spring that most years will not need.

Of the 34 crops in the fall planner, 29 still have a July-or-later last planting day in Pittsburgh once NC State Extension's days to harvest and University of Georgia Extension's harvest allowance of 18 days are counted back from frost. The other 5 do not. The slowest crop that still fits is Chinese cabbage, at 103 days, and it has to be planted by July 3 to beat the early date.

Worked example: a tomato plan for Pittsburgh

A gardener in Pittsburgh who follows University of New Hampshire Extension sets tomato transplants out one to two weeks after the last frost: April 25 to May 2 from the typical date of April 18, or May 13 to May 20 from the late date of May 6, 18 days later.

To have transplants ready on the first day of the late window, sow seeds six to eight weeks earlier, between March 18 and April 1.

That leaves 147 days against 75 to 85 days for the plants to reach harvest, so even the late schedule fits in an early-frost year with 62 days to spare.

About the Pittsburgh Allegheny CO AP station

The station lies 6.5 miles south-east of Pittsburgh's internal point, farther than most on these pages, so treat its dates as a regional guide.

NOAA lists it at about 1,250 feet, higher than 75 and lower than 24 of the 100 stations in this set. In NOAA's file the record is marked R, meaning representative.

No elevation is available for Pittsburgh in the Census data we saved, so the station's height may or may not match your garden's. Compare nearby stations in the frost dates tool if it does not, and err toward the colder dates.

Pittsburgh compared with nearby cities

The nearest city on these pages is Cleveland, OH, 114 miles away, and the other two below are farther out, so these are regional comparisons, not neighbors. Note that the Cleveland station stands 670 feet lower than Pittsburgh's.

• Cleveland, OH, 114 miles to the north-west: last frost April 8, first frost November 12, 217 days frost-free; its last frost comes 10 days before Pittsburgh's, and the frost-free season is 24 days longer than Pittsburgh's.
• Columbus, OH lies 162 miles west of Pittsburgh. Typical last frost April 20, first frost October 24, 185 days between; its last frost is nearly the same as Pittsburgh's, and the frost-free season is 8 days shorter than Pittsburgh's.
• Buffalo, NY, 179 miles to the north: last frost April 24, first frost October 26, 183 days frost-free; the last frost is 6 days later than in Pittsburgh, and it has 10 days less without frost.

Take these dates further

Open the frost dates tool with this station already chosen to see the whole ladder of probability dates, or try the nearby stations in the same list. The spring planting planner and the fall planting planner turn the same dates into a full crop list, and the hardiness zone lookup tells you which perennials will survive the winter.

Every city covered is on the city frost dates index, sorted by state.

Where these numbers come from

NOAA's U.S. Climate Normals for 1991–2020 (doi:10.25921/4ek7-fk11) supply every frost date here, unchanged from the station's record, and NOAA's documentation defines the probabilities. The Census Bureau's 2024 Gazetteer places Pittsburgh on the map, and its Vintage 2024 estimates, 307,668 people here, decide which cities get a page.

Planting dates here are those rules from University of New Hampshire Extension, NC State Extension and University of Georgia Extension, applied to this station's frost dates and nothing else. Our methodology describes the tests behind every number.

NOAA's dates say how often frost has come, not when it will. Check the forecast before planting and keep a cover on hand.