Frost dates for 17320Fairfield, PA
The average last spring frost in Fairfield is April 15 and the average first fall frost is October 27, giving a typical growing season of about 194 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 15
- Average first fall frost
- Oct 27
- Growing season
- 194 days
Safer after May 4 (1-in-10 risk)
Possible by Oct 11 (1-in-10 risk)
Last frost typically in 163 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 15 · Apr 30 · May 18 | Oct 3 · Oct 15 · Oct 28 | 170 days | 100% |
| Frost / freeze (32°F) | Apr 1 · Apr 15 · May 4 | Oct 11 · Oct 27 · Nov 10 | 194 days | 100% |
| Hard freeze (28°F) | Mar 21 · Apr 3 · Apr 17 | Oct 26 · Nov 8 · Nov 23 | 217 days | 100% |
Planting calendar for Fairfield
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 15 – May 21 |
| Tomatoes | Transplant outdoors | May 1 – Jul 7 |
| Peppers | Start seeds indoors | Mar 15 – Apr 15 |
| Peppers | Transplant outdoors | May 15 – Jun 15 |
| Eggplant | Start seeds indoors | Apr 1 – Apr 30 |
| Eggplant | Transplant outdoors | May 15 – Jun 15 |
| Cucumbers | Sow outdoors | May 15 – Jul 17 |
| Summer squash | Sow outdoors | May 1 – Jun 15 |
| Winter squash & pumpkins | Sow outdoors | May 15 – Jun 15 |
| Snap beans | Sow outdoors | May 1 – Aug 9 |
| Sweet corn | Sow outdoors | May 1 – Jul 7 |
| Watermelon & cantaloupe | Sow outdoors | May 15 – Jun 15 |
| Okra | Sow outdoors | May 8 – May 31 |
| Peas | Sow outdoors (spring) | Mar 15 – Apr 30 |
| Potatoes | Plant outdoors (spring) | Mar 15 – May 15 |
| Onions | Start seeds indoors (spring) | Feb 1 – Feb 28 |
| Onions | Transplant outdoors (spring) | Apr 1 – Apr 30 |
| Broccoli | Start seeds indoors (spring) | Feb 25 – Mar 31 |
| Broccoli | Transplant outdoors (spring) | Apr 1 – Apr 30 |
| Broccoli | Start seeds indoors (fall) | Jun 27 – Jul 7 |
| Broccoli | Transplant outdoors (fall) | Jul 27 – Aug 7 |
| Cabbage | Start seeds indoors (spring) | Feb 15 – Mar 15 |
| Cabbage | Transplant outdoors (spring) | Mar 15 – Apr 15 |
| Cabbage | Start seeds indoors (fall) | Jun 17 – Jul 17 |
| Cabbage | Transplant outdoors (fall) | Jul 17 – Aug 17 |
| Leaf lettuce | Sow outdoors (spring) | Mar 15 – May 31 |
| Leaf lettuce | Sow outdoors (fall) | Jul 17 – Sep 2 |
| Spinach | Sow outdoors (spring) | Mar 8 – Apr 21 |
| Spinach | Sow outdoors (fall) | Aug 3 – Sep 7 |
| Radishes | Sow outdoors (spring) | Mar 15 – May 5 |
| Radishes | Sow outdoors (fall) | Jul 17 – Sep 17 |
| Kale | Sow outdoors (spring) | Apr 1 – Apr 21 |
| Kale | Sow outdoors (fall) | Jul 10 – Aug 17 |
| Carrots | Sow outdoors (spring) | Apr 15 – May 31 |
| Carrots | Sow outdoors (fall) | Jun 17 – Aug 2 |
| Garlic | Plant outdoors (fall) | Oct 17 – Nov 17 |
Where these dates come from
ZIP code 17320 is matched to the NOAA station Biglerville, PA, 19.4 km away, at 720 ft elevation (11 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Biglerville, PA (used) | 720 ft | Apr 15 | Oct 27 |
| Cashtown 1S, PA | 710 ft | Apr 28 | Oct 17 |
| Eisenhower Nhs, PA | 540 ft | Apr 24 | Oct 21 |
| Emmitsburg 2 Se, MD | 403 ft | Apr 22 | Oct 20 |
Frost dates near Fairfield
- Emmitsburg, MD 21727 · last Apr 22, first Oct 20
- Mc Knightstown, PA 17343 · last Apr 15, first Oct 27
- Blue Ridge Summit, PA 17214 · last Apr 27, first Oct 20
- Orrtanna, PA 17353 · last Apr 15, first Oct 27
- Cashtown, PA 17310 · last Apr 15, first Oct 27
- South Mountain, PA 17261 · last Apr 27, first Oct 20
- Gettysburg, PA 17325 · last Apr 24, first Oct 21
- Sabillasville, MD 21780 · last Apr 14, first Oct 30
Frequently asked questions
- When is the last frost in Fairfield, PA?
- For ZIP code 17320, the average last spring frost (32°F) is April 15, based on NOAA 1991-2020 climate normals for the Biglerville, PA weather station. There is a 1-in-10 chance of a frost after May 4.
- When is the first frost in Fairfield, PA?
- The average first fall frost (32°F) is October 27. 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 17320?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 194 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.