Frost dates for 83203Fort Hall, ID
The average last spring frost in Fort Hall is May 20 and the average first fall frost is September 20, giving a typical growing season of about 119 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 20
- Average first fall frost
- Sep 20
- Growing season
- 119 days
Safer after Jun 12 (1-in-10 risk)
Possible by Sep 1 (1-in-10 risk)
Last frost typically in 205 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 23 · Jun 10 · Jun 27 | Aug 20 · Sep 7 · Sep 23 | 86 days | 100% |
| Frost / freeze (32°F) | May 6 · May 20 · Jun 12 | Sep 1 · Sep 20 · Oct 7 | 119 days | 100% |
| Hard freeze (28°F) | Apr 23 · May 6 · May 23 | Sep 15 · Oct 4 · Oct 20 | 149 days | 100% |
Planting calendar for Fort Hall
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 19 – Jun 25 |
| Tomatoes | Transplant outdoors | Jun 5 – May 31 |
| Peppers | Start seeds indoors | Apr 19 – May 20 |
| Peppers | Transplant outdoors | Jun 19 – Jul 20 |
| Eggplant | Start seeds indoors | May 6 – Jun 4 |
| Eggplant | Transplant outdoors | Jun 19 – Jul 20 |
| Cucumbers | Sow outdoors | Jun 19 – Jun 10 |
| Summer squash | Sow outdoors | Jun 5 – Jul 20 |
| Winter squash & pumpkins | Sow outdoors | Jun 19 – Jul 20 |
| Snap beans | Sow outdoors | Jun 5 – Jul 3 |
| Sweet corn | Sow outdoors | Jun 5 – May 31 |
| Watermelon & cantaloupe | Sow outdoors | Jun 19 – Jul 20 |
| Okra | Sow outdoors | Jun 12 – Jul 5 |
| Peas | Sow outdoors (spring) | Apr 19 – Jun 4 |
| Potatoes | Plant outdoors (spring) | Apr 19 – Jun 19 |
| Onions | Start seeds indoors (spring) | Mar 8 – Apr 4 |
| Onions | Transplant outdoors (spring) | May 6 – Jun 4 |
| Broccoli | Start seeds indoors (spring) | Apr 1 – May 5 |
| Broccoli | Transplant outdoors (spring) | May 6 – Jun 4 |
| Broccoli | Start seeds indoors (fall) | May 21 – May 31 |
| Broccoli | Transplant outdoors (fall) | Jun 20 – Jul 1 |
| Cabbage | Start seeds indoors (spring) | Mar 22 – Apr 19 |
| Cabbage | Transplant outdoors (spring) | Apr 19 – May 20 |
| Cabbage | Start seeds indoors (fall) | May 11 – Jun 10 |
| Cabbage | Transplant outdoors (fall) | Jun 10 – Jul 11 |
| Leaf lettuce | Sow outdoors (spring) | Apr 19 – Jul 5 |
| Leaf lettuce | Sow outdoors (fall) | Jun 10 – Jul 27 |
| Spinach | Sow outdoors (spring) | Apr 12 – May 26 |
| Spinach | Sow outdoors (fall) | Jun 27 – Aug 1 |
| Radishes | Sow outdoors (spring) | Apr 19 – Jun 9 |
| Radishes | Sow outdoors (fall) | Jun 10 – Aug 11 |
| Kale | Sow outdoors (spring) | May 6 – May 26 |
| Kale | Sow outdoors (fall) | Jun 3 – Jul 11 |
| Carrots | Sow outdoors (spring) | May 20 – Jul 5 |
| Carrots | Sow outdoors (fall) | May 11 – Jun 26 |
| Garlic | Plant outdoors (fall) | Sep 10 – Oct 11 |
Where these dates come from
ZIP code 83203 is matched to the NOAA station Ft Hall 1 Nne, ID, 1.6 km away, at 4,465 ft elevation (16 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Ft Hall 1 Nne, ID (used) | 4,465 ft | May 20 | Sep 20 |
| Pocatello 2 Ne, ID | 4,832 ft | May 16 | Oct 2 |
| Pocatello Rgnl Ap, ID | 4,478 ft | May 23 | Sep 18 |
| Pocatello City, ID | 4,460 ft | May 2 | Oct 11 |
Frost dates near Fort Hall
- Pocatello, ID 83202 · last May 2, first Oct 11
- Blackfoot, ID 83221 · last May 5, first Oct 3
- Pingree, ID 83262 · last May 20, first Sep 20
- Springfield, ID 83277 · last May 21, first Sep 20
- Moreland, ID 83256 · last May 5, first Oct 3
- Inkom, ID 83245 · last May 23, first Sep 24
- Aberdeen, ID 83210 · last May 21, first Sep 20
- Firth, ID 83236 · last May 5, first Oct 3
Frequently asked questions
- When is the last frost in Fort Hall, ID?
- For ZIP code 83203, the average last spring frost (32°F) is May 20, based on NOAA 1991-2020 climate normals for the Ft Hall 1 Nne, ID weather station. There is a 1-in-10 chance of a frost after June 12.
- When is the first frost in Fort Hall, ID?
- The average first fall frost (32°F) is September 20. 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 83203?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 119 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.