Frost dates for 69345Harrisburg, NE
The average last spring frost in Harrisburg is May 24 and the average first fall frost is September 20, giving a typical growing season of about 117 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 24
- Average first fall frost
- Sep 20
- Growing season
- 117 days
Safer after Jun 12 (1-in-10 risk)
Possible by Sep 6 (1-in-10 risk)
Last frost typically in 202 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) | May 22 · Jun 6 · Jun 23 | Aug 28 · Sep 12 · Sep 24 | 97 days | 100% |
| Frost / freeze (32°F) | May 11 · May 24 · Jun 12 | Sep 6 · Sep 20 · Oct 3 | 117 days | 100% |
| Hard freeze (28°F) | Apr 29 · May 12 · May 28 | Sep 13 · Sep 29 · Oct 12 | 137 days | 100% |
Planting calendar for Harrisburg
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 | Apr 23 – Jun 29 |
| Tomatoes | Transplant outdoors | Jun 9 – May 31 |
| Peppers | Start seeds indoors | Apr 23 – May 24 |
| Peppers | Transplant outdoors | Jun 23 – Jul 24 |
| Eggplant | Start seeds indoors | May 10 – Jun 8 |
| Eggplant | Transplant outdoors | Jun 23 – Jul 24 |
| Cucumbers | Sow outdoors | Jun 23 – Jun 10 |
| Summer squash | Sow outdoors | Jun 9 – Jul 24 |
| Winter squash & pumpkins | Sow outdoors | Jun 23 – Jul 24 |
| Snap beans | Sow outdoors | Jun 9 – Jul 3 |
| Sweet corn | Sow outdoors | Jun 9 – May 31 |
| Watermelon & cantaloupe | Sow outdoors | Jun 23 – Jul 24 |
| Okra | Sow outdoors | Jun 16 – Jul 9 |
| Peas | Sow outdoors (spring) | Apr 23 – Jun 8 |
| Potatoes | Plant outdoors (spring) | Apr 23 – Jun 23 |
| Onions | Start seeds indoors (spring) | Mar 12 – Apr 8 |
| Onions | Transplant outdoors (spring) | May 10 – Jun 8 |
| Broccoli | Start seeds indoors (spring) | Apr 5 – May 9 |
| Broccoli | Transplant outdoors (spring) | May 10 – Jun 8 |
| Broccoli | Start seeds indoors (fall) | May 21 – May 31 |
| Broccoli | Transplant outdoors (fall) | Jun 20 – Jul 1 |
| Cabbage | Start seeds indoors (spring) | Mar 26 – Apr 23 |
| Cabbage | Transplant outdoors (spring) | Apr 23 – May 24 |
| Cabbage | Start seeds indoors (fall) | May 11 – Jun 10 |
| Cabbage | Transplant outdoors (fall) | Jun 10 – Jul 11 |
| Leaf lettuce | Sow outdoors (spring) | Apr 23 – Jul 9 |
| Leaf lettuce | Sow outdoors (fall) | Jun 10 – Jul 27 |
| Spinach | Sow outdoors (spring) | Apr 16 – May 30 |
| Spinach | Sow outdoors (fall) | Jun 27 – Aug 1 |
| Radishes | Sow outdoors (spring) | Apr 23 – Jun 13 |
| Radishes | Sow outdoors (fall) | Jun 10 – Aug 11 |
| Kale | Sow outdoors (spring) | May 10 – May 30 |
| Kale | Sow outdoors (fall) | Jun 3 – Jul 11 |
| Carrots | Sow outdoors (spring) | May 24 – Jul 9 |
| Carrots | Sow outdoors (fall) | May 11 – Jun 26 |
| Garlic | Plant outdoors (fall) | Sep 10 – Oct 11 |
Where these dates come from
ZIP code 69345 is matched to the NOAA station Harrisburg 12Wnw, NE, 22.1 km away, at 4,550 ft elevation (3 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Harrisburg 12Wnw, NE (used) | 4,550 ft | May 24 | Sep 20 |
| Bridgeport 18Wsw, NE | 4,149 ft | May 19 | Sep 23 |
| Kimball 2Ne, NE | 4,708 ft | May 15 | Sep 26 |
| Scottsbluff 1E, NE | 3,909 ft | May 8 | Oct 3 |
Frost dates near Harrisburg
- Melbeta, NE 69355 · last May 5, first Oct 4
- Gering, NE 69341 · last May 8, first Oct 3
- Mcgrew, NE 69353 · last May 5, first Oct 4
- Scottsbluff, NE 69363 · last May 8, first Oct 3
- Kimball, NE 69145 · last May 15, first Sep 26
- Minatare, NE 69356 · last May 5, first Oct 4
- Albin, WY 82050 · last May 14, first Oct 2
- Bayard, NE 69334 · last May 8, first Oct 3
Frequently asked questions
- When is the last frost in Harrisburg, NE?
- For ZIP code 69345, the average last spring frost (32°F) is May 24, based on NOAA 1991-2020 climate normals for the Harrisburg 12Wnw, NE weather station. There is a 1-in-10 chance of a frost after June 12.
- When is the first frost in Harrisburg, NE?
- The average first fall frost (32°F) is September 20. There is a 1-in-10 chance of frost by September 6, so tender plants are at risk from that point on.
- How long is the growing season in 69345?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 117 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.