Frost dates for 83349Richfield, ID
The average last spring frost in Richfield is May 24 and the average first fall frost is September 26, giving a typical growing season of about 123 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 24
- Average first fall frost
- Sep 26
- Growing season
- 123 days
Safer after Jun 14 (1-in-10 risk)
Possible by Sep 10 (1-in-10 risk)
Last frost typically in 209 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 11 · Jun 27 | Sep 1 · Sep 14 · Sep 27 | 93 days | 100% |
| Frost / freeze (32°F) | May 6 · May 24 · Jun 14 | Sep 10 · Sep 26 · Oct 10 | 123 days | 100% |
| Hard freeze (28°F) | Apr 23 · May 8 · May 28 | Sep 23 · Oct 7 · Oct 22 | 152 days | 100% |
Planting calendar for Richfield
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 23 – Jun 29 |
| Tomatoes | Transplant outdoors | Jun 9 – Jun 6 |
| Peppers | Start seeds indoors | Apr 23 – May 24 |
| Peppers | Transplant outdoors | Jun 23 – Jul 24 |
| Eggplant | Start seeds indoors | May 10 – Jun 8 |
| Eggplant | Transplant outdoors | Jun 23 – Jul 24 |
| Cucumbers | Sow outdoors | Jun 23 – Jun 16 |
| Summer squash | Sow outdoors | Jun 9 – Jul 24 |
| Winter squash & pumpkins | Sow outdoors | Jun 23 – Jul 24 |
| Snap beans | Sow outdoors | Jun 9 – Jul 9 |
| Sweet corn | Sow outdoors | Jun 9 – Jun 6 |
| Watermelon & cantaloupe | Sow outdoors | Jun 23 – Jul 24 |
| Okra | Sow outdoors | Jun 16 – Jul 9 |
| Peas | Sow outdoors (spring) | Apr 23 – Jun 8 |
| Potatoes | Plant outdoors (spring) | Apr 23 – Jun 23 |
| Onions | Start seeds indoors (spring) | Mar 12 – Apr 8 |
| Onions | Transplant outdoors (spring) | May 10 – Jun 8 |
| Broccoli | Start seeds indoors (spring) | Apr 5 – May 9 |
| Broccoli | Transplant outdoors (spring) | May 10 – Jun 8 |
| Broccoli | Start seeds indoors (fall) | May 27 – Jun 6 |
| Broccoli | Transplant outdoors (fall) | Jun 26 – Jul 7 |
| Cabbage | Start seeds indoors (spring) | Mar 26 – Apr 23 |
| Cabbage | Transplant outdoors (spring) | Apr 23 – May 24 |
| Cabbage | Start seeds indoors (fall) | May 17 – Jun 16 |
| Cabbage | Transplant outdoors (fall) | Jun 16 – Jul 17 |
| Leaf lettuce | Sow outdoors (spring) | Apr 23 – Jul 9 |
| Leaf lettuce | Sow outdoors (fall) | Jun 16 – Aug 2 |
| Spinach | Sow outdoors (spring) | Apr 16 – May 30 |
| Spinach | Sow outdoors (fall) | Jul 3 – Aug 7 |
| Radishes | Sow outdoors (spring) | Apr 23 – Jun 13 |
| Radishes | Sow outdoors (fall) | Jun 16 – Aug 17 |
| Kale | Sow outdoors (spring) | May 10 – May 30 |
| Kale | Sow outdoors (fall) | Jun 9 – Jul 17 |
| Carrots | Sow outdoors (spring) | May 24 – Jul 9 |
| Carrots | Sow outdoors (fall) | May 17 – Jul 2 |
| Garlic | Plant outdoors (fall) | Sep 16 – Oct 17 |
Where these dates come from
ZIP code 83349 is matched to the NOAA station Richfield, ID, 0.9 km away, at 4,309 ft elevation (25 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Richfield, ID (used) | 4,309 ft | May 24 | Sep 26 |
| Shoshone 1 Wnw, ID | 3,950 ft | Apr 24 | Oct 16 |
| Picabo, ID | 4,839 ft | Jun 16 | Sep 9 |
| Jerome Co Ap, ID | 4,048 ft | May 1 | Oct 14 |
Frost dates near Richfield
- Dietrich, ID 83324 · last Apr 24, first Oct 16
- Shoshone, ID 83352 · last Apr 24, first Oct 16
- Picabo, ID 83348 · last Jun 16, first Sep 9
- Carey, ID 83320 · last Jun 16, first Sep 9
- Bellevue, ID 83313 · last May 13, first Oct 2
- Jerome, ID 83338 · last May 2, first Oct 14
- Gooding, ID 83330 · last May 2, first Oct 14
- Hazelton, ID 83335 · last May 7, first Oct 5
Frequently asked questions
- When is the last frost in Richfield, ID?
- For ZIP code 83349, the average last spring frost (32°F) is May 24, based on NOAA 1991-2020 climate normals for the Richfield, ID weather station. There is a 1-in-10 chance of a frost after June 14.
- When is the first frost in Richfield, ID?
- The average first fall frost (32°F) is September 26. There is a 1-in-10 chance of frost by September 10, so tender plants are at risk from that point on.
- How long is the growing season in 83349?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 123 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.