Frost dates for 19421Birchrunville, PA
The average last spring frost in Birchrunville is April 19 and the average first fall frost is October 25, giving a typical growing season of about 190 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 19
- Average first fall frost
- Oct 25
- Growing season
- 190 days
Safer after May 4 (1-in-10 risk)
Possible by Oct 11 (1-in-10 risk)
Last frost typically in 167 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 18 · May 1 · May 17 | Oct 1 · Oct 13 · Oct 26 | 165 days | 100% |
| Frost / freeze (32°F) | Apr 3 · Apr 19 · May 4 | Oct 11 · Oct 25 · Nov 7 | 190 days | 100% |
| Hard freeze (28°F) | Mar 19 · Apr 3 · Apr 18 | Oct 24 · Nov 6 · Nov 21 | 216 days | 100% |
Planting calendar for Birchrunville
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 19 – May 25 |
| Tomatoes | Transplant outdoors | May 5 – Jul 5 |
| Peppers | Start seeds indoors | Mar 19 – Apr 19 |
| Peppers | Transplant outdoors | May 19 – Jun 19 |
| Eggplant | Start seeds indoors | Apr 5 – May 4 |
| Eggplant | Transplant outdoors | May 19 – Jun 19 |
| Cucumbers | Sow outdoors | May 19 – Jul 15 |
| Summer squash | Sow outdoors | May 5 – Jun 19 |
| Winter squash & pumpkins | Sow outdoors | May 19 – Jun 19 |
| Snap beans | Sow outdoors | May 5 – Aug 7 |
| Sweet corn | Sow outdoors | May 5 – Jul 5 |
| Watermelon & cantaloupe | Sow outdoors | May 19 – Jun 19 |
| Okra | Sow outdoors | May 12 – Jun 4 |
| Peas | Sow outdoors (spring) | Mar 19 – May 4 |
| Potatoes | Plant outdoors (spring) | Mar 19 – May 19 |
| Onions | Start seeds indoors (spring) | Feb 5 – Mar 4 |
| Onions | Transplant outdoors (spring) | Apr 5 – May 4 |
| Broccoli | Start seeds indoors (spring) | Mar 1 – Apr 4 |
| Broccoli | Transplant outdoors (spring) | Apr 5 – May 4 |
| Broccoli | Start seeds indoors (fall) | Jun 25 – Jul 5 |
| Broccoli | Transplant outdoors (fall) | Jul 25 – Aug 5 |
| Cabbage | Start seeds indoors (spring) | Feb 19 – Mar 19 |
| Cabbage | Transplant outdoors (spring) | Mar 19 – Apr 19 |
| Cabbage | Start seeds indoors (fall) | Jun 15 – Jul 15 |
| Cabbage | Transplant outdoors (fall) | Jul 15 – Aug 15 |
| Leaf lettuce | Sow outdoors (spring) | Mar 19 – Jun 4 |
| Leaf lettuce | Sow outdoors (fall) | Jul 15 – Aug 31 |
| Spinach | Sow outdoors (spring) | Mar 12 – Apr 25 |
| Spinach | Sow outdoors (fall) | Aug 1 – Sep 5 |
| Radishes | Sow outdoors (spring) | Mar 19 – May 9 |
| Radishes | Sow outdoors (fall) | Jul 15 – Sep 15 |
| Kale | Sow outdoors (spring) | Apr 5 – Apr 25 |
| Kale | Sow outdoors (fall) | Jul 8 – Aug 15 |
| Carrots | Sow outdoors (spring) | Apr 19 – Jun 4 |
| Carrots | Sow outdoors (fall) | Jun 15 – Jul 31 |
| Garlic | Plant outdoors (fall) | Oct 15 – Nov 15 |
Where these dates come from
ZIP code 19421 is matched to the NOAA station Coatesville 2 W, PA, 9.5 km away, at 640 ft elevation (128 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Coatesville 2 W, PA (used) | 640 ft | Apr 19 | Oct 25 |
| W Chester 2 Nw, PA | 375 ft | Apr 26 | Oct 18 |
| Glenmoore, PA | 500 ft | Apr 11 | Nov 1 |
| Avondale 2 N, PA | 400 ft | Apr 19 | Oct 26 |
Frost dates near Birchrunville
- Wagontown, PA 19376 · last Apr 19, first Oct 25
- Southeastern, PA 19397 · last Apr 19, first Oct 25
- Thorndale, PA 19372 · last Apr 26, first Oct 18
- Downingtown, PA 19335 · last Apr 26, first Oct 18
- Modena, PA 19358 · last Apr 26, first Oct 18
- Coatesville, PA 19320 · last Apr 19, first Oct 25
- Lyndell, PA 19354 · last Apr 26, first Oct 18
- Unionville, PA 19375 · last Apr 26, first Oct 18
Frequently asked questions
- When is the last frost in Birchrunville, PA?
- For ZIP code 19421, the average last spring frost (32°F) is April 19, based on NOAA 1991-2020 climate normals for the Coatesville 2 W, PA weather station. There is a 1-in-10 chance of a frost after May 4.
- When is the first frost in Birchrunville, PA?
- The average first fall frost (32°F) is October 25. There is a 1-in-10 chance of frost by October 11, so tender plants are at risk from that point on.
- How long is the growing season in 19421?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 190 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.