When to plant in Jefferson Hills, PA
Planting dates worked out from Jefferson Hills's own frost records, not a generic zone chart.
Safe to plant out
Apr 29
1 year in 10 has a later frost
Average last frost
Apr 18
about a 50% chance of a later one
Average first fall frost
Oct 24
1 year in 10 by Oct 8
Frost-free days
186
median, 1991–2020
Station used: Pittsburgh Allegheny Co Ap · 7.2 km away · station 379 m, town 315 m. How we match towns to stations
This season
Plan your garden.
Planting dates for common crops
| Crop | Start indoors | Plant out or sow | Harvest from |
|---|---|---|---|
| Tomato | Mar 4 – Mar 18 | Apr 29 – May 13 | Jun 23 |
| Sweet pepper | Feb 18 – Mar 4 | Apr 29 – May 13 | Jun 28 |
| Lettuce (leaf) | Feb 14 – Feb 21 | Mar 21 – Apr 4 | Apr 30 |
| Peas | — | Mar 21 – Apr 18 | May 15 |
| Bush beans | — | Apr 22 – May 13 | Jun 11 |
| Carrot | — | Mar 30 – May 11 | May 29 |
| Beet | — | Mar 30 – May 11 | May 19 |
| Potato | — | Mar 30 – Apr 20 | Jun 8 |
| Kale | Feb 14 – Feb 28 | Mar 28 – Apr 11 | May 10 |
| Broccoli | Feb 7 – Feb 21 | Mar 21 – Apr 11 | May 20 |
| Cucumber | Apr 1 – Apr 8 | Apr 29 – May 13 | Jun 18 |
| Summer squash and zucchini | Apr 1 – Apr 8 | Apr 29 – May 13 | Jun 13 |
| Winter squash | Apr 1 – Apr 8 | Apr 29 – May 13 | Jul 18 |
| Sweet corn | — | Apr 22 – May 13 | Jun 21 |
| Onion (from sets) | — | Mar 21 – Apr 11 | Jun 19 |
| Garlic | — | Oct 10 – Nov 7 (fall) | following summer |
| Spinach | — | Mar 21 – Apr 18 | Apr 28 |
| Basil | Mar 18 – Apr 1 | Apr 29 – May 13 | Jun 25 |
Jefferson Hills's weather over time
How the growing season has shifted here, year by year, from the station's own records.
Each year's last spring frostLong-term trend
See the data as a table
| Year | Last spring frost |
|---|---|
| 1936 | Apr 23 |
| 1937 | Apr 12 |
| 1938 | Apr 10 |
| 1939 | Apr 14 |
| 1946 | Apr 28 |
| 1947 | May 10 |
| 1948 | Apr 17 |
| 1949 | Apr 17 |
| 1950 | Apr 16 |
| 1951 | Apr 20 |
| 1952 | Apr 11 |
| 1999 | Mar 27 |
| 2000 | Apr 13 |
| 2001 | Apr 19 |
| 2002 | Apr 24 |
| 2003 | Apr 6 |
| 2004 | Apr 28 |
| 2005 | Apr 24 |
| 2006 | Apr 26 |
| 2007 | Apr 10 |
| 2008 | Apr 16 |
| 2009 | Apr 13 |
| 2010 | Apr 28 |
| 2011 | Apr 6 |
| 2012 | Apr 11 |
| 2013 | May 14 |
| 2014 | Apr 16 |
| 2015 | Apr 25 |
| 2016 | Apr 13 |
| 2017 | Apr 8 |
| 2018 | Apr 29 |
| 2019 | Apr 2 |
| 2020 | May 9 |
| 2021 | Apr 26 |
| 2022 | Apr 28 |
| 2023 | Apr 25 |
| 2024 | Mar 30 |
Each year's frost-free daysLong-term trend
See the data as a table
| Year | Frost-free days |
|---|---|
| 1936 | 185 |
| 1937 | 184 |
| 1938 | 179 |
| 1946 | 198 |
| 1947 | 143 |
| 1948 | 184 |
| 1949 | 198 |
| 1950 | 207 |
| 1951 | 194 |
| 1999 | 211 |
| 2000 | 177 |
| 2001 | 171 |
| 2002 | 190 |
| 2003 | 179 |
| 2004 | 172 |
| 2005 | 188 |
| 2006 | 168 |
| 2007 | 201 |
| 2008 | 185 |
| 2009 | 188 |
| 2010 | 184 |
| 2011 | 204 |
| 2012 | 208 |
| 2013 | 163 |
| 2014 | 200 |
| 2015 | 175 |
| 2016 | 212 |
| 2017 | 213 |
| 2018 | 172 |
| 2019 | 212 |
| 2020 | 160 |
| 2021 | 191 |
| 2022 | 199 |
| 2023 | 180 |
| 2024 | 227 |
Each year's average temperature, April to SeptemberLong-term trend
See the data as a table
| Year | Growing-season temperature |
|---|---|
| 1936 | 18.9 °C |
| 1937 | 18.4 °C |
| 1938 | 18.6 °C |
| 1946 | 18.0 °C |
| 1947 | 18.6 °C |
| 1948 | 18.9 °C |
| 1949 | 18.9 °C |
| 1950 | 17.6 °C |
| 1951 | 18.5 °C |
| 1952 | 19.3 °C |
| 1999 | 19.3 °C |
| 2000 | 18.0 °C |
| 2001 | 18.4 °C |
| 2002 | 19.2 °C |
| 2003 | 18.1 °C |
| 2004 | 18.2 °C |
| 2005 | 19.5 °C |
| 2006 | 18.3 °C |
| 2007 | 18.9 °C |
| 2008 | 18.5 °C |
| 2009 | 18.2 °C |
| 2010 | 20.1 °C |
| 2011 | 19.6 °C |
| 2012 | 19.7 °C |
| 2013 | 18.8 °C |
| 2014 | 18.9 °C |
| 2015 | 19.5 °C |
| 2016 | 19.7 °C |
| 2017 | 19.1 °C |
| 2018 | 19.4 °C |
| 2019 | 19.7 °C |
| 2020 | 18.9 °C |
| 2021 | 19.2 °C |
| 2022 | 19.3 °C |
| 2023 | 18.9 °C |
| 2024 | 21.0 °C |
What this means for you: Since 1936, Jefferson Hills's last spring frost has stayed at about the same time of year. Year-to-year swings are large, so keep using the safe date rather than the trend.
Source: daily records from Pittsburgh Allegheny Co Ap (NOAA GHCN-Daily). Years with too many missing days are left out.