Frost dates for 51555Missouri Valley, IA
The average last spring frost in Missouri Valley is April 29 and the average first fall frost is October 8, giving a typical growing season of about 162 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 29
- Average first fall frost
- Oct 8
- Growing season
- 162 days
Safer after May 13 (1-in-10 risk)
Possible by Sep 23 (1-in-10 risk)
Last frost typically in 184 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 25 · May 7 · May 21 | Sep 17 · Oct 1 · Oct 12 | 146 days | 100% |
| Frost / freeze (32°F) | Apr 15 · Apr 29 · May 13 | Sep 23 · Oct 8 · Oct 22 | 162 days | 100% |
| Hard freeze (28°F) | Apr 6 · Apr 19 · May 3 | Oct 3 · Oct 19 · Nov 1 | 181 days | 100% |
Planting calendar for Missouri Valley
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 29 – Jun 4 |
| Tomatoes | Transplant outdoors | May 15 – Jun 18 |
| Peppers | Start seeds indoors | Mar 29 – Apr 29 |
| Peppers | Transplant outdoors | May 29 – Jun 29 |
| Eggplant | Start seeds indoors | Apr 15 – May 14 |
| Eggplant | Transplant outdoors | May 29 – Jun 29 |
| Cucumbers | Sow outdoors | May 29 – Jun 28 |
| Summer squash | Sow outdoors | May 15 – Jun 29 |
| Winter squash & pumpkins | Sow outdoors | May 29 – Jun 29 |
| Snap beans | Sow outdoors | May 15 – Jul 21 |
| Sweet corn | Sow outdoors | May 15 – Jun 18 |
| Watermelon & cantaloupe | Sow outdoors | May 29 – Jun 29 |
| Okra | Sow outdoors | May 22 – Jun 14 |
| Peas | Sow outdoors (spring) | Mar 29 – May 14 |
| Potatoes | Plant outdoors (spring) | Mar 29 – May 29 |
| Onions | Start seeds indoors (spring) | Feb 15 – Mar 14 |
| Onions | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (spring) | Mar 11 – Apr 14 |
| Broccoli | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (fall) | Jun 8 – Jun 18 |
| Broccoli | Transplant outdoors (fall) | Jul 8 – Jul 19 |
| Cabbage | Start seeds indoors (spring) | Mar 1 – Mar 29 |
| Cabbage | Transplant outdoors (spring) | Mar 29 – Apr 29 |
| Cabbage | Start seeds indoors (fall) | May 29 – Jun 28 |
| Cabbage | Transplant outdoors (fall) | Jun 28 – Jul 29 |
| Leaf lettuce | Sow outdoors (spring) | Mar 29 – Jun 14 |
| Leaf lettuce | Sow outdoors (fall) | Jun 28 – Aug 14 |
| Spinach | Sow outdoors (spring) | Mar 22 – May 5 |
| Spinach | Sow outdoors (fall) | Jul 15 – Aug 19 |
| Radishes | Sow outdoors (spring) | Mar 29 – May 19 |
| Radishes | Sow outdoors (fall) | Jun 28 – Aug 29 |
| Kale | Sow outdoors (spring) | Apr 15 – May 5 |
| Kale | Sow outdoors (fall) | Jun 21 – Jul 29 |
| Carrots | Sow outdoors (spring) | Apr 29 – Jun 14 |
| Carrots | Sow outdoors (fall) | May 29 – Jul 14 |
| Garlic | Plant outdoors (fall) | Sep 28 – Oct 29 |
Where these dates come from
ZIP code 51555 is matched to the NOAA station Logan, IA, 11.9 km away, at 990 ft elevation (211 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Logan, IA (used) | 990 ft | Apr 29 | Oct 8 |
| Blair, NE | 1,090 ft | Apr 22 | Oct 17 |
| Ft Calhoun 4W, NE | 1,310 ft | Apr 19 | Oct 17 |
| Omaha #1, NE | 1,280 ft | Apr 16 | Oct 18 |
Frost dates near Missouri Valley
- Modale, IA 51556 · last Apr 29, first Oct 8
- Honey Creek, IA 51542 · last Apr 18, first Oct 21
- Logan, IA 51546 · last Apr 29, first Oct 8
- Magnolia, IA 51550 · last Apr 29, first Oct 8
- Fort Calhoun, NE 68023 · last Apr 19, first Oct 17
- Mondamin, IA 51557 · last May 1, first Oct 3
- Neola, IA 51559 · last Apr 23, first Oct 14
- Blair, NE 68008 · last Apr 19, first Oct 17
Frequently asked questions
- When is the last frost in Missouri Valley, IA?
- For ZIP code 51555, the average last spring frost (32°F) is April 29, based on NOAA 1991-2020 climate normals for the Logan, IA weather station. There is a 1-in-10 chance of a frost after May 13.
- When is the first frost in Missouri Valley, IA?
- The average first fall frost (32°F) is October 8. There is a 1-in-10 chance of frost by September 23, so tender plants are at risk from that point on.
- How long is the growing season in 51555?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 162 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.