Frost dates for 17311Codorus, PA
The average last spring frost in Codorus is April 26 and the average first fall frost is October 19, giving a typical growing season of about 177 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 26
- Average first fall frost
- Oct 19
- Growing season
- 177 days
Safer after May 13 (1-in-10 risk)
Possible by Oct 5 (1-in-10 risk)
Last frost typically in 176 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 23 · May 8 · May 24 | Sep 25 · Oct 8 · Oct 22 | 153 days | 100% |
| Frost / freeze (32°F) | Apr 7 · Apr 26 · May 13 | Oct 5 · Oct 19 · Nov 1 | 177 days | 100% |
| Hard freeze (28°F) | Mar 24 · Apr 8 · Apr 26 | Oct 15 · Oct 31 · Nov 13 | 203 days | 100% |
Planting calendar for Codorus
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 26 – Jun 1 |
| Tomatoes | Transplant outdoors | May 12 – Jun 29 |
| Peppers | Start seeds indoors | Mar 26 – Apr 26 |
| Peppers | Transplant outdoors | May 26 – Jun 26 |
| Eggplant | Start seeds indoors | Apr 12 – May 11 |
| Eggplant | Transplant outdoors | May 26 – Jun 26 |
| Cucumbers | Sow outdoors | May 26 – Jul 9 |
| Summer squash | Sow outdoors | May 12 – Jun 26 |
| Winter squash & pumpkins | Sow outdoors | May 26 – Jun 26 |
| Snap beans | Sow outdoors | May 12 – Aug 1 |
| Sweet corn | Sow outdoors | May 12 – Jun 29 |
| Watermelon & cantaloupe | Sow outdoors | May 26 – Jun 26 |
| Okra | Sow outdoors | May 19 – Jun 11 |
| Peas | Sow outdoors (spring) | Mar 26 – May 11 |
| Potatoes | Plant outdoors (spring) | Mar 26 – May 26 |
| Onions | Start seeds indoors (spring) | Feb 12 – Mar 11 |
| Onions | Transplant outdoors (spring) | Apr 12 – May 11 |
| Broccoli | Start seeds indoors (spring) | Mar 8 – Apr 11 |
| Broccoli | Transplant outdoors (spring) | Apr 12 – May 11 |
| Broccoli | Start seeds indoors (fall) | Jun 19 – Jun 29 |
| Broccoli | Transplant outdoors (fall) | Jul 19 – Jul 30 |
| Cabbage | Start seeds indoors (spring) | Feb 26 – Mar 26 |
| Cabbage | Transplant outdoors (spring) | Mar 26 – Apr 26 |
| Cabbage | Start seeds indoors (fall) | Jun 9 – Jul 9 |
| Cabbage | Transplant outdoors (fall) | Jul 9 – Aug 9 |
| Leaf lettuce | Sow outdoors (spring) | Mar 26 – Jun 11 |
| Leaf lettuce | Sow outdoors (fall) | Jul 9 – Aug 25 |
| Spinach | Sow outdoors (spring) | Mar 19 – May 2 |
| Spinach | Sow outdoors (fall) | Jul 26 – Aug 30 |
| Radishes | Sow outdoors (spring) | Mar 26 – May 16 |
| Radishes | Sow outdoors (fall) | Jul 9 – Sep 9 |
| Kale | Sow outdoors (spring) | Apr 12 – May 2 |
| Kale | Sow outdoors (fall) | Jul 2 – Aug 9 |
| Carrots | Sow outdoors (spring) | Apr 26 – Jun 11 |
| Carrots | Sow outdoors (fall) | Jun 9 – Jul 25 |
| Garlic | Plant outdoors (fall) | Oct 9 – Nov 9 |
Where these dates come from
ZIP code 17311 is matched to the NOAA station York 3 Ssw Pump Stn, PA, 5.1 km away, at 390 ft elevation (269 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| York 3 Ssw Pump Stn, PA (used) | 390 ft | Apr 26 | Oct 19 |
| York Ap, PA | 486 ft | Apr 27 | Oct 18 |
| Millers 4 Ne, MD | 860 ft | Apr 19 | Oct 25 |
| Hanover 4 Sw, PA | 558 ft | Apr 24 | Oct 20 |
Frost dates near Codorus
- Seven Valleys, PA 17360 · last Apr 26, first Oct 19
- York New Salem, PA 17371 · last Apr 27, first Oct 18
- York, PA 17407 · last Apr 26, first Oct 19
- Loganville, PA 17342 · last Apr 19, first Oct 25
- Glen Rock, PA 17327 · last Apr 19, first Oct 25
- Dallastown, PA 17313 · last Apr 26, first Oct 19
- Spring Grove, PA 17362 · last Apr 27, first Oct 18
- Thomasville, PA 17364 · last Apr 27, first Oct 18
Frequently asked questions
- When is the last frost in Codorus, PA?
- For ZIP code 17311, the average last spring frost (32°F) is April 26, based on NOAA 1991-2020 climate normals for the York 3 Ssw Pump Stn, PA weather station. There is a 1-in-10 chance of a frost after May 13.
- When is the first frost in Codorus, PA?
- The average first fall frost (32°F) is October 19. There is a 1-in-10 chance of frost by October 5, so tender plants are at risk from that point on.
- How long is the growing season in 17311?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 177 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.