Frost dates for 83643Mesa, ID
The average last spring frost in Mesa is May 10 and the average first fall frost is October 2, giving a typical growing season of about 145 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 10
- Average first fall frost
- Oct 2
- Growing season
- 145 days
Safer after Jun 1 (1-in-10 risk)
Possible by Sep 16 (1-in-10 risk)
Last frost typically in 189 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 11 · Jun 1 · Jun 21 | Sep 4 · Sep 19 · Oct 3 | 109 days | 100% |
| Frost / freeze (32°F) | Apr 25 · May 10 · Jun 1 | Sep 16 · Oct 2 · Oct 18 | 145 days | 100% |
| Hard freeze (28°F) | Apr 4 · Apr 22 · May 8 | Oct 1 · Oct 16 · Oct 30 | 176 days | 100% |
Planting calendar for Mesa
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 9 – Jun 15 |
| Tomatoes | Transplant outdoors | May 26 – Jun 12 |
| Peppers | Start seeds indoors | Apr 9 – May 10 |
| Peppers | Transplant outdoors | Jun 9 – Jul 10 |
| Eggplant | Start seeds indoors | Apr 26 – May 25 |
| Eggplant | Transplant outdoors | Jun 9 – Jul 10 |
| Cucumbers | Sow outdoors | Jun 9 – Jun 22 |
| Summer squash | Sow outdoors | May 26 – Jul 10 |
| Winter squash & pumpkins | Sow outdoors | Jun 9 – Jul 10 |
| Snap beans | Sow outdoors | May 26 – Jul 15 |
| Sweet corn | Sow outdoors | May 26 – Jun 12 |
| Watermelon & cantaloupe | Sow outdoors | Jun 9 – Jul 10 |
| Okra | Sow outdoors | Jun 2 – Jun 25 |
| Peas | Sow outdoors (spring) | Apr 9 – May 25 |
| Potatoes | Plant outdoors (spring) | Apr 9 – Jun 9 |
| Onions | Start seeds indoors (spring) | Feb 26 – Mar 25 |
| Onions | Transplant outdoors (spring) | Apr 26 – May 25 |
| Broccoli | Start seeds indoors (spring) | Mar 22 – Apr 25 |
| Broccoli | Transplant outdoors (spring) | Apr 26 – May 25 |
| Broccoli | Start seeds indoors (fall) | Jun 2 – Jun 12 |
| Broccoli | Transplant outdoors (fall) | Jul 2 – Jul 13 |
| Cabbage | Start seeds indoors (spring) | Mar 12 – Apr 9 |
| Cabbage | Transplant outdoors (spring) | Apr 9 – May 10 |
| Cabbage | Start seeds indoors (fall) | May 23 – Jun 22 |
| Cabbage | Transplant outdoors (fall) | Jun 22 – Jul 23 |
| Leaf lettuce | Sow outdoors (spring) | Apr 9 – Jun 25 |
| Leaf lettuce | Sow outdoors (fall) | Jun 22 – Aug 8 |
| Spinach | Sow outdoors (spring) | Apr 2 – May 16 |
| Spinach | Sow outdoors (fall) | Jul 9 – Aug 13 |
| Radishes | Sow outdoors (spring) | Apr 9 – May 30 |
| Radishes | Sow outdoors (fall) | Jun 22 – Aug 23 |
| Kale | Sow outdoors (spring) | Apr 26 – May 16 |
| Kale | Sow outdoors (fall) | Jun 15 – Jul 23 |
| Carrots | Sow outdoors (spring) | May 10 – Jun 25 |
| Carrots | Sow outdoors (fall) | May 23 – Jul 8 |
| Garlic | Plant outdoors (fall) | Sep 22 – Oct 23 |
Where these dates come from
ZIP code 83643 is matched to the NOAA station Council, ID, 13.3 km away, at 2,943 ft elevation (279 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Council, ID (used) | 2,943 ft | May 10 | Oct 2 |
| Cambridge, ID | 2,650 ft | May 15 | Sep 27 |
| Cascade 1 Nw, ID | 4,896 ft | May 30 | Sep 19 |
| Mccall, ID | 5,025 ft | Jun 22 | Sep 2 |
Frost dates near Mesa
- Indian Valley, ID 83632 · last May 15, first Sep 27
- Council, ID 83612 · last May 10, first Oct 2
- Cambridge, ID 83610 · last May 15, first Sep 27
- Midvale, ID 83645 · last May 15, first Sep 27
- Donnelly, ID 83615 · last May 30, first Sep 19
- Lake Fork, ID 83635 · last Jun 10, first Sep 10
- McCall, ID 83638 · last Jun 22, first Sep 2
- New Meadows, ID 83654 · last —, first —
Frequently asked questions
- When is the last frost in Mesa, ID?
- For ZIP code 83643, the average last spring frost (32°F) is May 10, based on NOAA 1991-2020 climate normals for the Council, ID weather station. There is a 1-in-10 chance of a frost after June 1.
- When is the first frost in Mesa, ID?
- The average first fall frost (32°F) is October 2. There is a 1-in-10 chance of frost by September 16, so tender plants are at risk from that point on.
- How long is the growing season in 83643?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 145 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.