Frost dates for 19404 — Norristown, PA
Last spring frostApr 24median date
First fall frostOct 15median date
Growing season174 daysfrost-free
Hardiness zone7aZone 7a
How Norristown compares
- In 8 years out of 10, the last spring frost in Norristown falls between April 10 and May 9, a 29-day window. The first fall frost falls between October 1 and November 1.
- The median last frost is 3 days earlier than the Pennsylvania median of Apr 27.
- Its 174-day growing season is longer than 43% of the 1,787 Pennsylvania places with a regular frost season (state median 175 days).
- The last frost is 8 days later than the zone 7a median of Apr 16. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 7a chart.
- The weather station records an average of 137 nights a year at or below 32°F.
- Compared with Abington, PA, 23 km away, the last frost here is 13 days later than there and the growing season is 30 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 10 |
| 50% (median) | April 24 |
| 10% (safe for tender plants) | May 9 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 1 |
| 50% (median) | October 15 |
| 90% (late) | November 1 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Norristown, PA
Frost dates for 19404 — Norristown, PA — last frost Apr 24, first frost Oct 15, zone 7a. whenisthelastfrost.com
Crop
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Start indoors: Jan 30 to Feb 13Transplant outside: Mar 27 to Apr 10
Start indoors: Feb 13 to Feb 27Transplant outside: May 8 to May 22
Start indoors: Feb 13 to Feb 27Transplant outside: May 8 to May 22
Start indoors: Feb 27 to Mar 13Transplant outside: May 1 to May 15
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 3 to Apr 17Sow outdoors: Mar 27 to May 1Plant for fall: Aug 20 to Sep 17
Start indoors: Feb 27 to Mar 13Transplant outside: Mar 27 to Apr 10Sow outdoors: Mar 27 to Apr 10Plant for fall: Aug 6 to Aug 27
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 10 to Apr 24Plant for fall: Jul 9 to Jul 30
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 3 to Apr 17Plant for fall: Jul 9 to Jul 30
Start indoors: Feb 27 to Mar 13Transplant outside: Apr 10 to Apr 24Plant for fall: Jul 9 to Jul 30
Start indoors: Mar 13 to Mar 27Transplant outside: May 15 to May 29Sow outdoors: May 15 to May 29
Start indoors: Mar 13 to Mar 27Transplant outside: May 1 to May 15
Sow outdoors: Mar 13 to Apr 3Plant for fall: Jul 23 to Aug 13
Sow outdoors: Mar 13 to Apr 3Plant for fall: Aug 20 to Sep 10
Sow outdoors: Mar 20 to May 1Plant for fall: Sep 3 to Sep 24
Start indoors: Mar 27 to Apr 3Transplant outside: May 8 to May 15Sow outdoors: May 1 to May 15Plant for fall: Jul 30 to Aug 13
Start indoors: Mar 27 to Apr 3Sow outdoors: May 1 to May 15Plant for fall: Aug 6 to Aug 20
Start indoors: Mar 27 to Apr 3Sow outdoors: May 1 to May 15
Start indoors: Mar 27 to Apr 3Transplant outside: May 8 to May 22
Sow outdoors: Apr 3 to May 1Plant for fall: Jul 23 to Aug 6
Sow outdoors: Apr 3 to May 1Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 3 to Apr 24
Sow outdoors: Apr 10 to May 8Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 10 to May 1Plant for fall: Aug 20 to Sep 10
Sow outdoors: May 1 to May 22Plant for fall: Jul 30 to Aug 13
Sow outdoors: May 1 to May 15
Transplant outside: May 8 to May 29
Plant for fall: Oct 1 to Nov 5
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Norristown, PA
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 30 – Feb 13 | Mar 27 – Apr 10 | — | — |
| Peppers | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Eggplant | Feb 13 – Feb 27 | May 8 – May 22 | — | — |
| Tomatoes | Feb 27 – Mar 13 | May 1 – May 15 | — | — |
| Lettuce | Feb 27 – Mar 13 | Apr 3 – Apr 17 | Mar 27 – May 1 | Aug 20 – Sep 17 |
| Kale | Feb 27 – Mar 13 | Mar 27 – Apr 10 | Mar 27 – Apr 10 | Aug 6 – Aug 27 |
| Broccoli | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 9 – Jul 30 |
| Cabbage | Feb 27 – Mar 13 | Apr 3 – Apr 17 | — | Jul 9 – Jul 30 |
| Cauliflower | Feb 27 – Mar 13 | Apr 10 – Apr 24 | — | Jul 9 – Jul 30 |
| Okra | Mar 13 – Mar 27 | May 15 – May 29 | May 15 – May 29 | — |
| Basil | Mar 13 – Mar 27 | May 1 – May 15 | — | — |
| Peas | — | — | Mar 13 – Apr 3 | Jul 23 – Aug 13 |
| Spinach | — | — | Mar 13 – Apr 3 | Aug 20 – Sep 10 |
| Radishes | — | — | Mar 20 – May 1 | Sep 3 – Sep 24 |
| Cucumbers | Mar 27 – Apr 3 | May 8 – May 15 | May 1 – May 15 | Jul 30 – Aug 13 |
| Zucchini & Summer Squash | Mar 27 – Apr 3 | — | May 1 – May 15 | Aug 6 – Aug 20 |
| Winter Squash & Pumpkins | Mar 27 – Apr 3 | — | May 1 – May 15 | — |
| Melons & Watermelon | Mar 27 – Apr 3 | May 8 – May 22 | — | — |
| Carrots | — | — | Apr 3 – May 1 | Jul 23 – Aug 6 |
| Beets | — | — | Apr 3 – May 1 | Aug 6 – Aug 20 |
| Potatoes | — | — | Apr 3 – Apr 24 | — |
| Swiss Chard | — | — | Apr 10 – May 8 | Aug 6 – Aug 20 |
| Cilantro | — | — | Apr 10 – May 1 | Aug 20 – Sep 10 |
| Green Beans | — | — | May 1 – May 22 | Jul 30 – Aug 13 |
| Sweet Corn | — | — | May 1 – May 15 | — |
| Sweet Potatoes | — | May 8 – May 29 | — | — |
| Garlic | — | — | — | Oct 1 – Nov 5 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Graterford 1 E, PA weather station, 6 km away (elevation 279 ft (85 m)).
ZIP codes in Norristown: 19401 19403 19404
Frost dates near Norristown
- Audubon Apr 24 · Oct 15
- Lederach Apr 24 · Oct 15
- Mainland Apr 24 · Oct 15
- Cedars Apr 24 · Oct 15
- Worcester Apr 24 · Oct 15
- Kulpsville Apr 24 · Oct 15
- Skippack Apr 24 · Oct 15
- West Point Apr 24 · Oct 15
Frequently asked questions
When is the last frost in Norristown, PA?
The median last spring frost in Norristown, PA is April 24. There is still about a 10% chance of frost after May 9, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Norristown, PA?
The median first fall frost is October 15, with about a 10% chance of frost before October 1.
How long is the growing season in Norristown, PA?
About 174 days between the median last spring frost and first fall frost.
What planting zone is Norristown, PA?
Norristown, PA is in USDA hardiness zone 7a.