Last spring frost
Apr 13
Frost Dates for Monessen, PA
First fall frost
Nov 5
Growing season
205 days
Hardiness zone
6b
In an average year around Monessen, PA, the last spring frost (32°F) is about Apr 13 and the first fall frost is about Nov 5, giving roughly a 205-day growing season. To be safe most years, wait until Mar 29 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | May 16 | Apr 27 | Apr 11 |
| Freeze (32°F) | May 5 | Apr 13 | Mar 29 |
| Hard (28°F) | Apr 14 | Mar 31 | Mar 15 |
| Severe (24°F) | Apr 2 | Mar 20 | Mar 3 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 16 | May 9 | May 4 | Apr 30 | Apr 27 | Apr 24 | Apr 20 | Apr 17 | Apr 11 |
| 32°F | May 5 | Apr 26 | Apr 21 | Apr 17 | Apr 13 | Apr 8 | Apr 5 | Apr 2 | Mar 29 |
| 28°F | Apr 14 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 29 | Mar 25 | Mar 21 | Mar 15 |
| 24°F | Apr 2 | Mar 31 | Mar 27 | Mar 23 | Mar 20 | Mar 17 | Mar 13 | Mar 9 | Mar 3 |
| 20°F | Mar 25 | Mar 20 | Mar 16 | Mar 13 | Mar 9 | Mar 6 | Mar 2 | Feb 26 | Feb 18 |
| 16°F | Mar 17 | Mar 12 | Mar 8 | Mar 3 | Feb 28 | Feb 24 | Feb 18 | Feb 12 | Feb 5 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Oct 10 | Oct 25 | Nov 5 |
| Freeze (32°F) | Oct 25 | Nov 5 | Nov 18 |
| Hard (28°F) | Nov 3 | Nov 16 | Dec 3 |
| Severe (24°F) | Nov 9 | Nov 27 | Dec 16 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 10 | Oct 15 | Oct 20 | Oct 23 | Oct 25 | Oct 28 | Oct 30 | Nov 2 | Nov 5 |
| 32°F | Oct 25 | Oct 29 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 10 | Nov 14 | Nov 18 |
| 28°F | Nov 3 | Nov 7 | Nov 10 | Nov 12 | Nov 16 | Nov 19 | Nov 23 | Nov 28 | Dec 3 |
| 24°F | Nov 9 | Nov 14 | Nov 19 | Nov 23 | Nov 27 | Dec 1 | Dec 5 | Dec 9 | Dec 16 |
| 20°F | Nov 19 | Nov 26 | Dec 1 | Dec 5 | Dec 9 | Dec 14 | Dec 19 | Dec 23 | Dec 29 |
| 16°F | Dec 1 | Dec 9 | Dec 14 | Dec 20 | Dec 23 | Dec 28 | Jan 1 | Jan 7 | Jan 15 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Charleroi Lock 4, Pa, about 0.9 miles away@if(!empty($station['elevation_ft'])), at 749 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Monessen, PA?
On average, the last spring frost (32°F) around Monessen, PA is about Apr 13. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 29.
When is the first frost in the fall?
The first fall frost around Monessen, PA typically arrives about Nov 5. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Apr 13 on average, or Mar 29 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 205 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 15062 Planting calendar → Pennsylvania frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026