Frost dates for 83865Colburn, ID
The average last spring frost in Colburn is May 20 and the average first fall frost is September 13, giving a typical growing season of about 114 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 20
- Average first fall frost
- Sep 13
- Growing season
- 114 days
Safer after Jun 4 (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) | — | — | 74 days | 100% |
| Frost / freeze (32°F) | May 6 · May 20 · Jun 4 | Sep 1 · Sep 13 · Sep 30 | 114 days | 100% |
| Hard freeze (28°F) | Apr 19 · May 4 · May 17 | Sep 12 · Sep 28 · Oct 13 | 146 days | 100% |
Planting calendar for Colburn
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 24 |
| 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 3 |
| Summer squash | Sow outdoors | Jun 5 – Jul 20 |
| Winter squash & pumpkins | Sow outdoors | Jun 19 – Jul 20 |
| Snap beans | Sow outdoors | Jun 5 – Jun 26 |
| Sweet corn | Sow outdoors | Jun 5 – May 24 |
| 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 14 – May 24 |
| Broccoli | Transplant outdoors (fall) | Jun 13 – Jun 24 |
| Cabbage | Start seeds indoors (spring) | Mar 22 – Apr 19 |
| Cabbage | Transplant outdoors (spring) | Apr 19 – May 20 |
| Cabbage | Start seeds indoors (fall) | May 4 – Jun 3 |
| Cabbage | Transplant outdoors (fall) | Jun 3 – Jul 4 |
| Leaf lettuce | Sow outdoors (spring) | Apr 19 – Jul 5 |
| Leaf lettuce | Sow outdoors (fall) | Jun 3 – Jul 20 |
| Spinach | Sow outdoors (spring) | Apr 12 – May 26 |
| Spinach | Sow outdoors (fall) | Jun 20 – Jul 25 |
| Radishes | Sow outdoors (spring) | Apr 19 – Jun 9 |
| Radishes | Sow outdoors (fall) | Jun 3 – Aug 4 |
| Kale | Sow outdoors (spring) | May 6 – May 26 |
| Kale | Sow outdoors (fall) | May 27 – Jul 4 |
| Carrots | Sow outdoors (spring) | May 20 – Jul 5 |
| Carrots | Sow outdoors (fall) | May 4 – Jun 19 |
| Garlic | Plant outdoors (fall) | Sep 3 – Oct 4 |
Where these dates come from
ZIP code 83865 is matched to the NOAA station Priest Rvr Exp Stn, ID, 15.6 km away, at 2,371 ft elevation (2,396 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Priest Rvr Exp Stn, ID (used) | 2,371 ft | May 20 | Sep 13 |
| Sandpoint Exp Stn, ID | 2,126 ft | May 8 | Sep 28 |
| Newport, WA | 2,162 ft | May 12 | Sep 21 |
| Bayview Model Basin, ID | 2,087 ft | May 22 | Sep 22 |
Frost dates near Colburn
- Sandpoint, ID 83864 · last May 8, first Sep 28
- Ponderay, ID 83852 · last May 8, first Sep 28
- Kootenai, ID 83840 · last May 8, first Sep 28
- Dover, ID 83825 · last May 8, first Sep 28
- Sagle, ID 83860 · last May 8, first Sep 28
- Laclede, ID 83841 · last May 8, first Sep 28
- Coolin, ID 83821 · last May 20, first Sep 13
- Cocolalla, ID 83813 · last May 20, first Sep 13
Frequently asked questions
- When is the last frost in Colburn, ID?
- For ZIP code 83865, the average last spring frost (32°F) is May 20, based on NOAA 1991-2020 climate normals for the Priest Rvr Exp Stn, ID weather station. There is a 1-in-10 chance of a frost after June 4.
- When is the first frost in Colburn, ID?
- The average first fall frost (32°F) is September 13. 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 83865?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 114 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.