Frost dates for 18011Alburtis, PA
The average last spring frost in Alburtis is April 26 and the average first fall frost is October 14, giving a typical growing season of about 171 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 26
- Average first fall frost
- Oct 14
- Growing season
- 171 days
Safer after May 13 (1-in-10 risk)
Possible by Oct 1 (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 22 · May 8 · May 24 | Sep 24 · Oct 5 · Oct 18 | 151 days | 100% |
| Frost / freeze (32°F) | Apr 10 · Apr 26 · May 13 | Oct 1 · Oct 14 · Oct 31 | 171 days | 100% |
| Hard freeze (28°F) | Mar 29 · Apr 10 · Apr 29 | Oct 10 · Oct 26 · Nov 12 | 198 days | 100% |
Planting calendar for Alburtis
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 24 |
| 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 4 |
| Summer squash | Sow outdoors | May 12 – Jun 26 |
| Winter squash & pumpkins | Sow outdoors | May 26 – Jun 26 |
| Snap beans | Sow outdoors | May 12 – Jul 27 |
| Sweet corn | Sow outdoors | May 12 – Jun 24 |
| 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 14 – Jun 24 |
| Broccoli | Transplant outdoors (fall) | Jul 14 – Jul 25 |
| Cabbage | Start seeds indoors (spring) | Feb 26 – Mar 26 |
| Cabbage | Transplant outdoors (spring) | Mar 26 – Apr 26 |
| Cabbage | Start seeds indoors (fall) | Jun 4 – Jul 4 |
| Cabbage | Transplant outdoors (fall) | Jul 4 – Aug 4 |
| Leaf lettuce | Sow outdoors (spring) | Mar 26 – Jun 11 |
| Leaf lettuce | Sow outdoors (fall) | Jul 4 – Aug 20 |
| Spinach | Sow outdoors (spring) | Mar 19 – May 2 |
| Spinach | Sow outdoors (fall) | Jul 21 – Aug 25 |
| Radishes | Sow outdoors (spring) | Mar 26 – May 16 |
| Radishes | Sow outdoors (fall) | Jul 4 – Sep 4 |
| Kale | Sow outdoors (spring) | Apr 12 – May 2 |
| Kale | Sow outdoors (fall) | Jun 27 – Aug 4 |
| Carrots | Sow outdoors (spring) | Apr 26 – Jun 11 |
| Carrots | Sow outdoors (fall) | Jun 4 – Jul 20 |
| Garlic | Plant outdoors (fall) | Oct 4 – Nov 4 |
Where these dates come from
ZIP code 18011 is matched to the NOAA station Rodale Rsch Ctr, PA, 10.9 km away, at 550 ft elevation (107 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Rodale Rsch Ctr, PA (used) | 550 ft | Apr 26 | Oct 14 |
| Allentown Intl Ap, PA | 390 ft | Apr 20 | Oct 24 |
| Springtown 1 Nne, PA | 860 ft | Apr 21 | Oct 22 |
| Reading 4 Nnw, PA | 360 ft | Apr 10 | Oct 31 |
Frost dates near Alburtis
- Macungie, PA 18062 · last Apr 26, first Oct 14
- Trexlertown, PA 18087 · last Apr 26, first Oct 14
- East Texas, PA 18046 · last Apr 20, first Oct 24
- Breinigsville, PA 18031 · last Apr 26, first Oct 14
- Mertztown, PA 19539 · last Apr 26, first Oct 14
- Allentown, PA 18106 · last Apr 26, first Oct 14
- Old Zionsville, PA 18068 · last Apr 21, first Oct 22
- Maxatawny, PA 19538 · last Apr 26, first Oct 14
Frequently asked questions
- When is the last frost in Alburtis, PA?
- For ZIP code 18011, the average last spring frost (32°F) is April 26, based on NOAA 1991-2020 climate normals for the Rodale Rsch Ctr, PA weather station. There is a 1-in-10 chance of a frost after May 13.
- When is the first frost in Alburtis, PA?
- The average first fall frost (32°F) is October 14. There is a 1-in-10 chance of frost by October 1, so tender plants are at risk from that point on.
- How long is the growing season in 18011?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 171 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.