Frost dates for 57035Humboldt, SD
The average last spring frost in Humboldt is May 1 and the average first fall frost is October 6, giving a typical growing season of about 157 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 1
- Average first fall frost
- Oct 6
- Growing season
- 157 days
Safer after May 14 (1-in-10 risk)
Possible by Sep 23 (1-in-10 risk)
Last frost typically in 186 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 29 · May 10 · May 23 | Sep 14 · Sep 27 · Oct 10 | 139 days | 100% |
| Frost / freeze (32°F) | Apr 18 · May 1 · May 14 | Sep 23 · Oct 6 · Oct 20 | 157 days | 100% |
| Hard freeze (28°F) | Apr 8 · Apr 22 · May 5 | Oct 1 · Oct 17 · Oct 30 | 176 days | 100% |
Planting calendar for Humboldt
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 31 – Jun 6 |
| Tomatoes | Transplant outdoors | May 17 – Jun 16 |
| Peppers | Start seeds indoors | Mar 31 – May 1 |
| Peppers | Transplant outdoors | May 31 – Jul 1 |
| Eggplant | Start seeds indoors | Apr 17 – May 16 |
| Eggplant | Transplant outdoors | May 31 – Jul 1 |
| Cucumbers | Sow outdoors | May 31 – Jun 26 |
| Summer squash | Sow outdoors | May 17 – Jul 1 |
| Winter squash & pumpkins | Sow outdoors | May 31 – Jul 1 |
| Snap beans | Sow outdoors | May 17 – Jul 19 |
| Sweet corn | Sow outdoors | May 17 – Jun 16 |
| Watermelon & cantaloupe | Sow outdoors | May 31 – Jul 1 |
| Okra | Sow outdoors | May 24 – Jun 16 |
| Peas | Sow outdoors (spring) | Mar 31 – May 16 |
| Potatoes | Plant outdoors (spring) | Mar 31 – May 31 |
| Onions | Start seeds indoors (spring) | Feb 17 – Mar 16 |
| Onions | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (spring) | Mar 13 – Apr 16 |
| Broccoli | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (fall) | Jun 6 – Jun 16 |
| Broccoli | Transplant outdoors (fall) | Jul 6 – Jul 17 |
| Cabbage | Start seeds indoors (spring) | Mar 3 – Mar 31 |
| Cabbage | Transplant outdoors (spring) | Mar 31 – May 1 |
| Cabbage | Start seeds indoors (fall) | May 27 – Jun 26 |
| Cabbage | Transplant outdoors (fall) | Jun 26 – Jul 27 |
| Leaf lettuce | Sow outdoors (spring) | Mar 31 – Jun 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 26 – Aug 12 |
| Spinach | Sow outdoors (spring) | Mar 24 – May 7 |
| Spinach | Sow outdoors (fall) | Jul 13 – Aug 17 |
| Radishes | Sow outdoors (spring) | Mar 31 – May 21 |
| Radishes | Sow outdoors (fall) | Jun 26 – Aug 27 |
| Kale | Sow outdoors (spring) | Apr 17 – May 7 |
| Kale | Sow outdoors (fall) | Jun 19 – Jul 27 |
| Carrots | Sow outdoors (spring) | May 1 – Jun 16 |
| Carrots | Sow outdoors (fall) | May 27 – Jul 12 |
| Garlic | Plant outdoors (fall) | Sep 26 – Oct 27 |
Where these dates come from
ZIP code 57035 is matched to the NOAA station Sioux Falls, SD, 27.6 km away, at 1,430 ft elevation (178 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Sioux Falls, SD (used) | 1,430 ft | May 1 | Oct 6 |
| Salem 5Ne, SD | 1,594 ft | May 7 | Sep 29 |
| Montrose 8N, SD | 1,718 ft | May 3 | Oct 4 |
| Sioux Falls Wfo Ap, SD | 1,430 ft | Apr 26 | Oct 13 |
Frost dates near Humboldt
- Hartford, SD 57033 · last May 1, first Oct 6
- Montrose, SD 57048 · last May 7, first Sep 29
- Monroe, SD 57047 · last Apr 30, first Oct 7
- Canistota, SD 57012 · last Apr 30, first Oct 7
- Lyons, SD 57041 · last May 1, first Oct 4
- Crooks, SD 57020 · last May 1, first Oct 6
- Colton, SD 57018 · last May 5, first Sep 30
- Sioux Falls, SD 57107 · last May 1, first Oct 6
Frequently asked questions
- When is the last frost in Humboldt, SD?
- For ZIP code 57035, the average last spring frost (32°F) is May 1, based on NOAA 1991-2020 climate normals for the Sioux Falls, SD weather station. There is a 1-in-10 chance of a frost after May 14.
- When is the first frost in Humboldt, SD?
- The average first fall frost (32°F) is October 6. 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 57035?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 157 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.