Frost dates for 83234Downey, ID
The average last spring frost in Downey is May 31 and the average first fall frost is September 18, giving a typical growing season of about 110 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 31
- Average first fall frost
- Sep 18
- Growing season
- 110 days
Safer after Jun 16 (1-in-10 risk)
Possible by Sep 3 (1-in-10 risk)
Last frost typically in 216 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) | Jun 3 · Jun 17 · Jun 30 | Aug 23 · Sep 7 · Sep 21 | 80 days | 100% |
| Frost / freeze (32°F) | May 13 · May 31 · Jun 16 | Sep 3 · Sep 18 · Oct 5 | 110 days | 100% |
| Hard freeze (28°F) | Apr 23 · May 9 · May 31 | Sep 15 · Oct 1 · Oct 17 | 144 days | 100% |
Planting calendar for Downey
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 30 – Jul 6 |
| Tomatoes | Transplant outdoors | Jun 16 – May 29 |
| Peppers | Start seeds indoors | Apr 30 – May 31 |
| Peppers | Transplant outdoors | Jun 30 – Jul 31 |
| Eggplant | Start seeds indoors | May 17 – Jun 15 |
| Eggplant | Transplant outdoors | Jun 30 – Jul 31 |
| Cucumbers | Sow outdoors | Jun 30 – Jun 8 |
| Summer squash | Sow outdoors | Jun 16 – Jul 31 |
| Winter squash & pumpkins | Sow outdoors | Jun 30 – Jul 31 |
| Snap beans | Sow outdoors | Jun 16 – Jul 1 |
| Sweet corn | Sow outdoors | Jun 16 – May 29 |
| Watermelon & cantaloupe | Sow outdoors | Jun 30 – Jul 31 |
| Okra | Sow outdoors | Jun 23 – Jul 16 |
| Peas | Sow outdoors (spring) | Apr 30 – Jun 15 |
| Potatoes | Plant outdoors (spring) | Apr 30 – Jun 30 |
| Onions | Start seeds indoors (spring) | Mar 19 – Apr 15 |
| Onions | Transplant outdoors (spring) | May 17 – Jun 15 |
| Broccoli | Start seeds indoors (spring) | Apr 12 – May 16 |
| Broccoli | Transplant outdoors (spring) | May 17 – Jun 15 |
| Broccoli | Start seeds indoors (fall) | May 19 – May 29 |
| Broccoli | Transplant outdoors (fall) | Jun 18 – Jun 29 |
| Cabbage | Start seeds indoors (spring) | Apr 2 – Apr 30 |
| Cabbage | Transplant outdoors (spring) | Apr 30 – May 31 |
| Cabbage | Start seeds indoors (fall) | May 9 – Jun 8 |
| Cabbage | Transplant outdoors (fall) | Jun 8 – Jul 9 |
| Leaf lettuce | Sow outdoors (spring) | Apr 30 – Jul 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 8 – Jul 25 |
| Spinach | Sow outdoors (spring) | Apr 23 – Jun 6 |
| Spinach | Sow outdoors (fall) | Jun 25 – Jul 30 |
| Radishes | Sow outdoors (spring) | Apr 30 – Jun 20 |
| Radishes | Sow outdoors (fall) | Jun 8 – Aug 9 |
| Kale | Sow outdoors (spring) | May 17 – Jun 6 |
| Kale | Sow outdoors (fall) | Jun 1 – Jul 9 |
| Carrots | Sow outdoors (spring) | May 31 – Jul 16 |
| Carrots | Sow outdoors (fall) | May 9 – Jun 24 |
| Garlic | Plant outdoors (fall) | Sep 8 – Oct 9 |
Where these dates come from
ZIP code 83234 is matched to the NOAA station Downey, ID, 1.6 km away, at 4,865 ft elevation (56 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Downey, ID (used) | 4,865 ft | May 31 | Sep 18 |
| Lava Hot Springs, ID | 4,595 ft | May 21 | Sep 21 |
| Mccammon, ID | 4,770 ft | May 23 | Sep 24 |
| Malad City, ID | 4,470 ft | May 22 | Sep 20 |
Frost dates near Downey
- Swanlake, ID 83281 · last May 29, first Sep 17
- Arimo, ID 83214 · last May 23, first Sep 24
- Lava Hot Springs, ID 83246 · last May 21, first Sep 21
- Clifton, ID 83228 · last May 16, first Sep 28
- McCammon, ID 83250 · last May 23, first Sep 24
- Malad City, ID 83252 · last May 22, first Sep 20
- Pocatello, ID 83209 · last May 23, first Sep 24
- Grace, ID 83241 · last May 29, first Sep 17
Frequently asked questions
- When is the last frost in Downey, ID?
- For ZIP code 83234, the average last spring frost (32°F) is May 31, based on NOAA 1991-2020 climate normals for the Downey, ID weather station. There is a 1-in-10 chance of a frost after June 16.
- When is the first frost in Downey, ID?
- The average first fall frost (32°F) is September 18. There is a 1-in-10 chance of frost by September 3, so tender plants are at risk from that point on.
- How long is the growing season in 83234?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 110 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.