Frost dates for 83237Franklin, ID
The average last spring frost in Franklin is May 16 and the average first fall frost is September 28, giving a typical growing season of about 133 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 16
- Average first fall frost
- Sep 28
- Growing season
- 133 days
Safer after Jun 4 (1-in-10 risk)
Possible by Sep 14 (1-in-10 risk)
Last frost typically in 201 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 16 · Jun 3 · Jun 19 | Sep 3 · Sep 17 · Oct 1 | 102 days | 100% |
| Frost / freeze (32°F) | May 2 · May 16 · Jun 4 | Sep 14 · Sep 28 · Oct 14 | 133 days | 100% |
| Hard freeze (28°F) | Apr 13 · Apr 30 · May 13 | Sep 26 · Oct 10 · Oct 26 | 164 days | 100% |
Planting calendar for Franklin
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 15 – Jun 21 |
| Tomatoes | Transplant outdoors | Jun 1 – Jun 8 |
| Peppers | Start seeds indoors | Apr 15 – May 16 |
| Peppers | Transplant outdoors | Jun 15 – Jul 16 |
| Eggplant | Start seeds indoors | May 2 – May 31 |
| Eggplant | Transplant outdoors | Jun 15 – Jul 16 |
| Cucumbers | Sow outdoors | Jun 15 – Jun 18 |
| Summer squash | Sow outdoors | Jun 1 – Jul 16 |
| Winter squash & pumpkins | Sow outdoors | Jun 15 – Jul 16 |
| Snap beans | Sow outdoors | Jun 1 – Jul 11 |
| Sweet corn | Sow outdoors | Jun 1 – Jun 8 |
| Watermelon & cantaloupe | Sow outdoors | Jun 15 – Jul 16 |
| Okra | Sow outdoors | Jun 8 – Jul 1 |
| Peas | Sow outdoors (spring) | Apr 15 – May 31 |
| Potatoes | Plant outdoors (spring) | Apr 15 – Jun 15 |
| Onions | Start seeds indoors (spring) | Mar 4 – Mar 31 |
| Onions | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (spring) | Mar 28 – May 1 |
| Broccoli | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (fall) | May 29 – Jun 8 |
| Broccoli | Transplant outdoors (fall) | Jun 28 – Jul 9 |
| Cabbage | Start seeds indoors (spring) | Mar 18 – Apr 15 |
| Cabbage | Transplant outdoors (spring) | Apr 15 – May 16 |
| Cabbage | Start seeds indoors (fall) | May 19 – Jun 18 |
| Cabbage | Transplant outdoors (fall) | Jun 18 – Jul 19 |
| Leaf lettuce | Sow outdoors (spring) | Apr 15 – Jul 1 |
| Leaf lettuce | Sow outdoors (fall) | Jun 18 – Aug 4 |
| Spinach | Sow outdoors (spring) | Apr 8 – May 22 |
| Spinach | Sow outdoors (fall) | Jul 5 – Aug 9 |
| Radishes | Sow outdoors (spring) | Apr 15 – Jun 5 |
| Radishes | Sow outdoors (fall) | Jun 18 – Aug 19 |
| Kale | Sow outdoors (spring) | May 2 – May 22 |
| Kale | Sow outdoors (fall) | Jun 11 – Jul 19 |
| Carrots | Sow outdoors (spring) | May 16 – Jul 1 |
| Carrots | Sow outdoors (fall) | May 19 – Jul 4 |
| Garlic | Plant outdoors (fall) | Sep 18 – Oct 19 |
Where these dates come from
ZIP code 83237 is matched to the NOAA station Preston, ID, 10.7 km away, at 4,719 ft elevation (159 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Preston, ID (used) | 4,719 ft | May 16 | Sep 28 |
| Richmond, UT | 4,680 ft | May 11 | Oct 5 |
| Trenton, UT | 4,455 ft | May 17 | Sep 18 |
| Logan Cache Ap, UT | 4,454 ft | May 8 | Oct 2 |
Frost dates near Franklin
- Lewiston, UT 84320 · last May 17, first Sep 18
- Preston, ID 83263 · last May 16, first Sep 28
- Richmond, UT 84333 · last May 11, first Oct 5
- Weston, ID 83286 · last May 16, first Sep 28
- Trenton, UT 84338 · last May 17, first Sep 18
- Cornish, UT 84308 · last May 17, first Sep 18
- Dayton, ID 83232 · last May 16, first Sep 28
- Smithfield, UT 84335 · last May 8, first Oct 2
Frequently asked questions
- When is the last frost in Franklin, ID?
- For ZIP code 83237, the average last spring frost (32°F) is May 16, based on NOAA 1991-2020 climate normals for the Preston, ID weather station. There is a 1-in-10 chance of a frost after June 4.
- When is the first frost in Franklin, ID?
- The average first fall frost (32°F) is September 28. There is a 1-in-10 chance of frost by September 14, so tender plants are at risk from that point on.
- How long is the growing season in 83237?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 133 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.