Frost dates for 17844Mifflinburg, PA
The average last spring frost in Mifflinburg is April 26 and the average first fall frost is October 20, giving a typical growing season of about 176 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 26
- Average first fall frost
- Oct 20
- Growing season
- 176 days
Safer after May 11 (1-in-10 risk)
Possible by Oct 5 (1-in-10 risk)
Last frost typically in 174 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 6 · May 21 | Sep 25 · Oct 7 · Oct 21 | 154 days | 100% |
| Frost / freeze (32°F) | Apr 13 · Apr 26 · May 11 | Oct 5 · Oct 20 · Nov 1 | 176 days | 100% |
| Hard freeze (28°F) | Mar 31 · Apr 14 · Apr 28 | Oct 17 · Nov 1 · Nov 13 | 200 days | 100% |
Planting calendar for Mifflinburg
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 30 |
| 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 10 |
| Summer squash | Sow outdoors | May 12 – Jun 26 |
| Winter squash & pumpkins | Sow outdoors | May 26 – Jun 26 |
| Snap beans | Sow outdoors | May 12 – Aug 2 |
| Sweet corn | Sow outdoors | May 12 – Jun 30 |
| 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 20 – Jun 30 |
| Broccoli | Transplant outdoors (fall) | Jul 20 – Jul 31 |
| Cabbage | Start seeds indoors (spring) | Feb 26 – Mar 26 |
| Cabbage | Transplant outdoors (spring) | Mar 26 – Apr 26 |
| Cabbage | Start seeds indoors (fall) | Jun 10 – Jul 10 |
| Cabbage | Transplant outdoors (fall) | Jul 10 – Aug 10 |
| Leaf lettuce | Sow outdoors (spring) | Mar 26 – Jun 11 |
| Leaf lettuce | Sow outdoors (fall) | Jul 10 – Aug 26 |
| Spinach | Sow outdoors (spring) | Mar 19 – May 2 |
| Spinach | Sow outdoors (fall) | Jul 27 – Aug 31 |
| Radishes | Sow outdoors (spring) | Mar 26 – May 16 |
| Radishes | Sow outdoors (fall) | Jul 10 – Sep 10 |
| Kale | Sow outdoors (spring) | Apr 12 – May 2 |
| Kale | Sow outdoors (fall) | Jul 3 – Aug 10 |
| Carrots | Sow outdoors (spring) | Apr 26 – Jun 11 |
| Carrots | Sow outdoors (fall) | Jun 10 – Jul 26 |
| Garlic | Plant outdoors (fall) | Oct 10 – Nov 10 |
Where these dates come from
ZIP code 17844 is matched to the NOAA station Lewisburg, PA, 14.7 km away, at 500 ft elevation (45 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Lewisburg, PA (used) | 500 ft | Apr 26 | Oct 20 |
| Laurelton Ctr, PA | 800 ft | Apr 25 | Oct 19 |
| Selinsgrove Penn Vly Ap, PA | 444 ft | Apr 27 | Oct 16 |
| Selinsgrove 2 S, PA | 420 ft | Apr 25 | Oct 22 |
Frost dates near Mifflinburg
- Vicksburg, PA 17883 · last Apr 26, first Oct 20
- Penns Creek, PA 17862 · last Apr 26, first Oct 20
- New Berlin, PA 17855 · last Apr 26, first Oct 20
- Swengel, PA 17880 · last Apr 26, first Oct 20
- Hartleton, PA 17829 · last Apr 25, first Oct 19
- Millmont, PA 17845 · last Apr 25, first Oct 19
- Lewisburg, PA 17837 · last Apr 26, first Oct 20
- Laurelton, PA 17835 · last Apr 25, first Oct 19
Frequently asked questions
- When is the last frost in Mifflinburg, PA?
- For ZIP code 17844, the average last spring frost (32°F) is April 26, based on NOAA 1991-2020 climate normals for the Lewisburg, PA weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Mifflinburg, PA?
- The average first fall frost (32°F) is October 20. 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 17844?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 176 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.