Frost dates for 57429Brentford, SD
The average last spring frost in Brentford is May 6 and the average first fall frost is September 29, giving a typical growing season of about 144 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 6
- Average first fall frost
- Sep 29
- Growing season
- 144 days
Safer after May 20 (1-in-10 risk)
Possible by Sep 16 (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) | May 4 · May 17 · May 28 | Sep 8 · Sep 21 · Oct 4 | 127 days | 100% |
| Frost / freeze (32°F) | Apr 25 · May 6 · May 20 | Sep 16 · Sep 29 · Oct 12 | 144 days | 100% |
| Hard freeze (28°F) | Apr 15 · Apr 29 · May 11 | Sep 24 · Oct 7 · Oct 21 | 162 days | 100% |
Planting calendar for Brentford
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 5 – Jun 11 |
| Tomatoes | Transplant outdoors | May 22 – Jun 9 |
| Peppers | Start seeds indoors | Apr 5 – May 6 |
| Peppers | Transplant outdoors | Jun 5 – Jul 6 |
| Eggplant | Start seeds indoors | Apr 22 – May 21 |
| Eggplant | Transplant outdoors | Jun 5 – Jul 6 |
| Cucumbers | Sow outdoors | Jun 5 – Jun 19 |
| Summer squash | Sow outdoors | May 22 – Jul 6 |
| Winter squash & pumpkins | Sow outdoors | Jun 5 – Jul 6 |
| Snap beans | Sow outdoors | May 22 – Jul 12 |
| Sweet corn | Sow outdoors | May 22 – Jun 9 |
| Watermelon & cantaloupe | Sow outdoors | Jun 5 – Jul 6 |
| Okra | Sow outdoors | May 29 – Jun 21 |
| Peas | Sow outdoors (spring) | Apr 5 – May 21 |
| Potatoes | Plant outdoors (spring) | Apr 5 – Jun 5 |
| Onions | Start seeds indoors (spring) | Feb 22 – Mar 21 |
| Onions | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (spring) | Mar 18 – Apr 21 |
| Broccoli | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (fall) | May 30 – Jun 9 |
| Broccoli | Transplant outdoors (fall) | Jun 29 – Jul 10 |
| Cabbage | Start seeds indoors (spring) | Mar 8 – Apr 5 |
| Cabbage | Transplant outdoors (spring) | Apr 5 – May 6 |
| Cabbage | Start seeds indoors (fall) | May 20 – Jun 19 |
| Cabbage | Transplant outdoors (fall) | Jun 19 – Jul 20 |
| Leaf lettuce | Sow outdoors (spring) | Apr 5 – Jun 21 |
| Leaf lettuce | Sow outdoors (fall) | Jun 19 – Aug 5 |
| Spinach | Sow outdoors (spring) | Mar 29 – May 12 |
| Spinach | Sow outdoors (fall) | Jul 6 – Aug 10 |
| Radishes | Sow outdoors (spring) | Apr 5 – May 26 |
| Radishes | Sow outdoors (fall) | Jun 19 – Aug 20 |
| Kale | Sow outdoors (spring) | Apr 22 – May 12 |
| Kale | Sow outdoors (fall) | Jun 12 – Jul 20 |
| Carrots | Sow outdoors (spring) | May 6 – Jun 21 |
| Carrots | Sow outdoors (fall) | May 20 – Jul 5 |
| Garlic | Plant outdoors (fall) | Sep 19 – Oct 20 |
Where these dates come from
ZIP code 57429 is matched to the NOAA station Conde, SD, 17.2 km away, at 1,330 ft elevation (31 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Conde, SD (used) | 1,330 ft | May 6 | Sep 29 |
| Mellette 4 W, SD | 1,296 ft | May 11 | Sep 27 |
| Turton, SD | 1,335 ft | May 7 | Oct 3 |
| Aberdeen 3 E, SD | 1,301 ft | May 8 | Sep 29 |
Frost dates near Brentford
- Mellette, SD 57461 · last May 11, first Sep 27
- Conde, SD 57434 · last May 6, first Sep 29
- Stratford, SD 57474 · last May 9, first Sep 26
- Ashton, SD 57424 · last May 11, first Sep 27
- Mansfield, SD 57460 · last May 11, first Sep 27
- Turton, SD 57477 · last May 6, first Sep 29
- Warner, SD 57479 · last May 9, first Sep 26
- Ferney, SD 57439 · last May 6, first Sep 29
Frequently asked questions
- When is the last frost in Brentford, SD?
- For ZIP code 57429, the average last spring frost (32°F) is May 6, based on NOAA 1991-2020 climate normals for the Conde, SD weather station. There is a 1-in-10 chance of a frost after May 20.
- When is the first frost in Brentford, SD?
- The average first fall frost (32°F) is September 29. There is a 1-in-10 chance of frost by September 16, so tender plants are at risk from that point on.
- How long is the growing season in 57429?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 144 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.