Frost dates for 68920Alma, NE
The average last spring frost in Alma is April 25 and the average first fall frost is October 14, giving a typical growing season of about 170 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 25
- Average first fall frost
- Oct 14
- Growing season
- 170 days
Safer after May 7 (1-in-10 risk)
Possible by Sep 28 (1-in-10 risk)
Last frost typically in 180 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 21 · May 3 · May 15 | Sep 23 · Oct 5 · Oct 17 | 153 days | 100% |
| Frost / freeze (32°F) | Apr 10 · Apr 25 · May 7 | Sep 28 · Oct 14 · Oct 25 | 170 days | 100% |
| Hard freeze (28°F) | Mar 31 · Apr 14 · Apr 29 | Oct 6 · Oct 23 · Nov 4 | 190 days | 100% |
Planting calendar for Alma
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 25 – May 31 |
| Tomatoes | Transplant outdoors | May 11 – Jun 24 |
| Peppers | Start seeds indoors | Mar 25 – Apr 25 |
| Peppers | Transplant outdoors | May 25 – Jun 25 |
| Eggplant | Start seeds indoors | Apr 11 – May 10 |
| Eggplant | Transplant outdoors | May 25 – Jun 25 |
| Cucumbers | Sow outdoors | May 25 – Jul 4 |
| Summer squash | Sow outdoors | May 11 – Jun 25 |
| Winter squash & pumpkins | Sow outdoors | May 25 – Jun 25 |
| Snap beans | Sow outdoors | May 11 – Jul 27 |
| Sweet corn | Sow outdoors | May 11 – Jun 24 |
| Watermelon & cantaloupe | Sow outdoors | May 25 – Jun 25 |
| Okra | Sow outdoors | May 18 – Jun 10 |
| Peas | Sow outdoors (spring) | Mar 25 – May 10 |
| Potatoes | Plant outdoors (spring) | Mar 25 – May 25 |
| Onions | Start seeds indoors (spring) | Feb 11 – Mar 10 |
| Onions | Transplant outdoors (spring) | Apr 11 – May 10 |
| Broccoli | Start seeds indoors (spring) | Mar 7 – Apr 10 |
| Broccoli | Transplant outdoors (spring) | Apr 11 – May 10 |
| Broccoli | Start seeds indoors (fall) | Jun 14 – Jun 24 |
| Broccoli | Transplant outdoors (fall) | Jul 14 – Jul 25 |
| Cabbage | Start seeds indoors (spring) | Feb 25 – Mar 25 |
| Cabbage | Transplant outdoors (spring) | Mar 25 – Apr 25 |
| Cabbage | Start seeds indoors (fall) | Jun 4 – Jul 4 |
| Cabbage | Transplant outdoors (fall) | Jul 4 – Aug 4 |
| Leaf lettuce | Sow outdoors (spring) | Mar 25 – Jun 10 |
| Leaf lettuce | Sow outdoors (fall) | Jul 4 – Aug 20 |
| Spinach | Sow outdoors (spring) | Mar 18 – May 1 |
| Spinach | Sow outdoors (fall) | Jul 21 – Aug 25 |
| Radishes | Sow outdoors (spring) | Mar 25 – May 15 |
| Radishes | Sow outdoors (fall) | Jul 4 – Sep 4 |
| Kale | Sow outdoors (spring) | Apr 11 – May 1 |
| Kale | Sow outdoors (fall) | Jun 27 – Aug 4 |
| Carrots | Sow outdoors (spring) | Apr 25 – Jun 10 |
| Carrots | Sow outdoors (fall) | Jun 4 – Jul 20 |
| Garlic | Plant outdoors (fall) | Oct 4 – Nov 4 |
Where these dates come from
ZIP code 68920 is matched to the NOAA station Harlan Co Lake, NE, 12.9 km away, at 2,010 ft elevation (34 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Harlan Co Lake, NE (used) | 2,010 ft | Apr 25 | Oct 14 |
| Ragan, NE | 2,240 ft | Apr 24 | Oct 18 |
| Oxford 6Nnw, NE | 2,242 ft | May 1 | Oct 8 |
| Franklin #2, NE | 1,861 ft | Apr 30 | Oct 8 |
Frost dates near Alma
- Orleans, NE 68966 · last Apr 25, first Oct 14
- Republican City, NE 68971 · last Apr 25, first Oct 14
- Stamford, NE 68977 · last May 4, first Oct 4
- Naponee, NE 68960 · last Apr 25, first Oct 14
- Ragan, NE 68969 · last Apr 24, first Oct 18
- Long Island, KS 67647 · last Apr 25, first Oct 14
- Oxford, NE 68967 · last May 1, first Oct 8
- Atlanta, NE 68923 · last May 2, first Oct 11
Frequently asked questions
- When is the last frost in Alma, NE?
- For ZIP code 68920, the average last spring frost (32°F) is April 25, based on NOAA 1991-2020 climate normals for the Harlan Co Lake, NE weather station. There is a 1-in-10 chance of a frost after May 7.
- When is the first frost in Alma, NE?
- The average first fall frost (32°F) is October 14. There is a 1-in-10 chance of frost by September 28, so tender plants are at risk from that point on.
- How long is the growing season in 68920?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 170 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.