Frost dates for 51571Silver City, IA
The average last spring frost in Silver City is April 23 and the average first fall frost is October 11, giving a typical growing season of about 170 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 23
- Average first fall frost
- Oct 11
- Growing season
- 170 days
Safer after May 6 (1-in-10 risk)
Possible by Sep 27 (1-in-10 risk)
Last frost typically in 178 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 19 · May 3 · May 17 | Sep 19 · Oct 2 · Oct 15 | 151 days | 100% |
| Frost / freeze (32°F) | Apr 9 · Apr 23 · May 6 | Sep 27 · Oct 11 · Oct 25 | 170 days | 100% |
| Hard freeze (28°F) | Mar 29 · Apr 12 · Apr 27 | Oct 3 · Oct 21 · Nov 3 | 190 days | 100% |
Planting calendar for Silver City
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 23 – May 29 |
| Tomatoes | Transplant outdoors | May 9 – Jun 21 |
| Peppers | Start seeds indoors | Mar 23 – Apr 23 |
| Peppers | Transplant outdoors | May 23 – Jun 23 |
| Eggplant | Start seeds indoors | Apr 9 – May 8 |
| Eggplant | Transplant outdoors | May 23 – Jun 23 |
| Cucumbers | Sow outdoors | May 23 – Jul 1 |
| Summer squash | Sow outdoors | May 9 – Jun 23 |
| Winter squash & pumpkins | Sow outdoors | May 23 – Jun 23 |
| Snap beans | Sow outdoors | May 9 – Jul 24 |
| Sweet corn | Sow outdoors | May 9 – Jun 21 |
| Watermelon & cantaloupe | Sow outdoors | May 23 – Jun 23 |
| Okra | Sow outdoors | May 16 – Jun 8 |
| Peas | Sow outdoors (spring) | Mar 23 – May 8 |
| Potatoes | Plant outdoors (spring) | Mar 23 – May 23 |
| Onions | Start seeds indoors (spring) | Feb 9 – Mar 8 |
| Onions | Transplant outdoors (spring) | Apr 9 – May 8 |
| Broccoli | Start seeds indoors (spring) | Mar 5 – Apr 8 |
| Broccoli | Transplant outdoors (spring) | Apr 9 – May 8 |
| Broccoli | Start seeds indoors (fall) | Jun 11 – Jun 21 |
| Broccoli | Transplant outdoors (fall) | Jul 11 – Jul 22 |
| Cabbage | Start seeds indoors (spring) | Feb 23 – Mar 23 |
| Cabbage | Transplant outdoors (spring) | Mar 23 – Apr 23 |
| Cabbage | Start seeds indoors (fall) | Jun 1 – Jul 1 |
| Cabbage | Transplant outdoors (fall) | Jul 1 – Aug 1 |
| Leaf lettuce | Sow outdoors (spring) | Mar 23 – Jun 8 |
| Leaf lettuce | Sow outdoors (fall) | Jul 1 – Aug 17 |
| Spinach | Sow outdoors (spring) | Mar 16 – Apr 29 |
| Spinach | Sow outdoors (fall) | Jul 18 – Aug 22 |
| Radishes | Sow outdoors (spring) | Mar 23 – May 13 |
| Radishes | Sow outdoors (fall) | Jul 1 – Sep 1 |
| Kale | Sow outdoors (spring) | Apr 9 – Apr 29 |
| Kale | Sow outdoors (fall) | Jun 24 – Aug 1 |
| Carrots | Sow outdoors (spring) | Apr 23 – Jun 8 |
| Carrots | Sow outdoors (fall) | Jun 1 – Jul 17 |
| Garlic | Plant outdoors (fall) | Oct 1 – Nov 1 |
Where these dates come from
ZIP code 51571 is matched to the NOAA station Glenwood 3Sw, IA, 16.8 km away, at 980 ft elevation (53 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Glenwood 3Sw, IA (used) | 980 ft | Apr 23 | Oct 11 |
| Oakland, IA | 1,260 ft | Apr 23 | Oct 14 |
| Omaha Eppley Airfield, NE | 982 ft | Apr 18 | Oct 21 |
| Springfield 7E, NE | 1,065 ft | Apr 17 | Oct 19 |
Frost dates near Silver City
- Mineola, IA 51554 · last Apr 23, first Oct 11
- Glenwood, IA 51534 · last Apr 23, first Oct 11
- Malvern, IA 51551 · last Apr 23, first Oct 11
- Treynor, IA 51575 · last Apr 23, first Oct 14
- Henderson, IA 51541 · last Apr 24, first Oct 13
- Hastings, IA 51540 · last Apr 24, first Oct 13
- Pacific Junction, IA 51561 · last Apr 23, first Oct 11
- Macedonia, IA 51549 · last Apr 23, first Oct 14
Frequently asked questions
- When is the last frost in Silver City, IA?
- For ZIP code 51571, the average last spring frost (32°F) is April 23, based on NOAA 1991-2020 climate normals for the Glenwood 3Sw, IA weather station. There is a 1-in-10 chance of a frost after May 6.
- When is the first frost in Silver City, IA?
- The average first fall frost (32°F) is October 11. There is a 1-in-10 chance of frost by September 27, so tender plants are at risk from that point on.
- How long is the growing season in 51571?
- 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.