Frost dates for 83217Bancroft, ID
The average last spring frost in Bancroft is May 29 and the average first fall frost is September 17, giving a typical growing season of about 111 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 29
- Average first fall frost
- Sep 17
- Growing season
- 111 days
Safer after Jun 16 (1-in-10 risk)
Possible by Sep 1 (1-in-10 risk)
Last frost typically in 214 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 29 · Jun 16 · Jul 5 | Aug 22 · Sep 4 · Sep 19 | 78 days | 100% |
| Frost / freeze (32°F) | May 11 · May 29 · Jun 16 | Sep 1 · Sep 17 · Oct 1 | 111 days | 100% |
| Hard freeze (28°F) | Apr 27 · May 9 · May 25 | Sep 15 · Oct 1 · Oct 16 | 143 days | 100% |
Planting calendar for Bancroft
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 28 – Jul 4 |
| Tomatoes | Transplant outdoors | Jun 14 – May 28 |
| Peppers | Start seeds indoors | Apr 28 – May 29 |
| Peppers | Transplant outdoors | Jun 28 – Jul 29 |
| Eggplant | Start seeds indoors | May 15 – Jun 13 |
| Eggplant | Transplant outdoors | Jun 28 – Jul 29 |
| Cucumbers | Sow outdoors | Jun 28 – Jun 7 |
| Summer squash | Sow outdoors | Jun 14 – Jul 29 |
| Winter squash & pumpkins | Sow outdoors | Jun 28 – Jul 29 |
| Snap beans | Sow outdoors | Jun 14 – Jun 30 |
| Sweet corn | Sow outdoors | Jun 14 – May 28 |
| Watermelon & cantaloupe | Sow outdoors | Jun 28 – Jul 29 |
| Okra | Sow outdoors | Jun 21 – Jul 14 |
| Peas | Sow outdoors (spring) | Apr 28 – Jun 13 |
| Potatoes | Plant outdoors (spring) | Apr 28 – Jun 28 |
| Onions | Start seeds indoors (spring) | Mar 17 – Apr 13 |
| Onions | Transplant outdoors (spring) | May 15 – Jun 13 |
| Broccoli | Start seeds indoors (spring) | Apr 10 – May 14 |
| Broccoli | Transplant outdoors (spring) | May 15 – Jun 13 |
| Broccoli | Start seeds indoors (fall) | May 18 – May 28 |
| Broccoli | Transplant outdoors (fall) | Jun 17 – Jun 28 |
| Cabbage | Start seeds indoors (spring) | Mar 31 – Apr 28 |
| Cabbage | Transplant outdoors (spring) | Apr 28 – May 29 |
| Cabbage | Start seeds indoors (fall) | May 8 – Jun 7 |
| Cabbage | Transplant outdoors (fall) | Jun 7 – Jul 8 |
| Leaf lettuce | Sow outdoors (spring) | Apr 28 – Jul 14 |
| Leaf lettuce | Sow outdoors (fall) | Jun 7 – Jul 24 |
| Spinach | Sow outdoors (spring) | Apr 21 – Jun 4 |
| Spinach | Sow outdoors (fall) | Jun 24 – Jul 29 |
| Radishes | Sow outdoors (spring) | Apr 28 – Jun 18 |
| Radishes | Sow outdoors (fall) | Jun 7 – Aug 8 |
| Kale | Sow outdoors (spring) | May 15 – Jun 4 |
| Kale | Sow outdoors (fall) | May 31 – Jul 8 |
| Carrots | Sow outdoors (spring) | May 29 – Jul 14 |
| Carrots | Sow outdoors (fall) | May 8 – Jun 23 |
| Garlic | Plant outdoors (fall) | Sep 7 – Oct 8 |
Where these dates come from
ZIP code 83217 is matched to the NOAA station Grace, ID, 17.6 km away, at 5,550 ft elevation (58 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Grace, ID (used) | 5,550 ft | May 29 | Sep 17 |
| Lava Hot Springs, ID | 4,595 ft | May 21 | Sep 21 |
| Soda Springs Ap, ID | 5,842 ft | — | — |
| Mccammon, ID | 4,770 ft | May 23 | Sep 24 |
Frost dates near Bancroft
- Lava Hot Springs, ID 83246 · last May 21, first Sep 21
- Conda, ID 83230 · last —, first —
- Grace, ID 83241 · last May 29, first Sep 17
- Soda Springs, ID 83276 · last —, first —
- McCammon, ID 83250 · last May 23, first Sep 24
- Arimo, ID 83214 · last May 23, first Sep 24
- Inkom, ID 83245 · last May 23, first Sep 24
- Pocatello, ID 83209 · last May 23, first Sep 24
Frequently asked questions
- When is the last frost in Bancroft, ID?
- For ZIP code 83217, the average last spring frost (32°F) is May 29, based on NOAA 1991-2020 climate normals for the Grace, ID weather station. There is a 1-in-10 chance of a frost after June 16.
- When is the first frost in Bancroft, ID?
- The average first fall frost (32°F) is September 17. There is a 1-in-10 chance of frost by September 1, so tender plants are at risk from that point on.
- How long is the growing season in 83217?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 111 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.