Frost dates for 81502Grand Junction, CO
The average last spring frost in Grand Junction is April 23 and the average first fall frost is October 20, giving a typical growing season of about 179 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 23
- Average first fall frost
- Oct 20
- Growing season
- 179 days
Safer after May 9 (1-in-10 risk)
Possible by Oct 5 (1-in-10 risk)
Last frost typically in 178 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) | Apr 21 · May 3 · May 20 | Sep 28 · Oct 10 · Oct 25 | 158 days | 100% |
| Frost / freeze (32°F) | Apr 6 · Apr 23 · May 9 | Oct 5 · Oct 20 · Nov 5 | 179 days | 100% |
| Hard freeze (28°F) | Mar 18 · Apr 8 · Apr 25 | Oct 14 · Nov 1 · Nov 15 | 207 days | 100% |
Planting calendar for Grand Junction
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 | Mar 23 – May 29 |
| Tomatoes | Transplant outdoors | May 9 – Jun 30 |
| Peppers | Start seeds indoors | Mar 23 – Apr 23 |
| Peppers | Transplant outdoors | May 23 – Jun 23 |
| Eggplant | Start seeds indoors | Apr 9 – May 8 |
| Eggplant | Transplant outdoors | May 23 – Jun 23 |
| Cucumbers | Sow outdoors | May 23 – Jul 10 |
| Summer squash | Sow outdoors | May 9 – Jun 23 |
| Winter squash & pumpkins | Sow outdoors | May 23 – Jun 23 |
| Snap beans | Sow outdoors | May 9 – Aug 2 |
| Sweet corn | Sow outdoors | May 9 – Jun 30 |
| Watermelon & cantaloupe | Sow outdoors | May 23 – Jun 23 |
| Okra | Sow outdoors | May 16 – Jun 8 |
| Peas | Sow outdoors (spring) | Mar 23 – May 8 |
| Potatoes | Plant outdoors (spring) | Mar 23 – May 23 |
| Onions | Start seeds indoors (spring) | Feb 9 – Mar 8 |
| Onions | Transplant outdoors (spring) | Apr 9 – May 8 |
| Broccoli | Start seeds indoors (spring) | Mar 5 – Apr 8 |
| Broccoli | Transplant outdoors (spring) | Apr 9 – May 8 |
| Broccoli | Start seeds indoors (fall) | Jun 20 – Jun 30 |
| Broccoli | Transplant outdoors (fall) | Jul 20 – Jul 31 |
| Cabbage | Start seeds indoors (spring) | Feb 23 – Mar 23 |
| Cabbage | Transplant outdoors (spring) | Mar 23 – Apr 23 |
| Cabbage | Start seeds indoors (fall) | Jun 10 – Jul 10 |
| Cabbage | Transplant outdoors (fall) | Jul 10 – Aug 10 |
| Leaf lettuce | Sow outdoors (spring) | Mar 23 – Jun 8 |
| Leaf lettuce | Sow outdoors (fall) | Jul 10 – Aug 26 |
| Spinach | Sow outdoors (spring) | Mar 16 – Apr 29 |
| Spinach | Sow outdoors (fall) | Jul 27 – Aug 31 |
| Radishes | Sow outdoors (spring) | Mar 23 – May 13 |
| Radishes | Sow outdoors (fall) | Jul 10 – Sep 10 |
| Kale | Sow outdoors (spring) | Apr 9 – Apr 29 |
| Kale | Sow outdoors (fall) | Jul 3 – Aug 10 |
| Carrots | Sow outdoors (spring) | Apr 23 – Jun 8 |
| Carrots | Sow outdoors (fall) | Jun 10 – Jul 26 |
| Garlic | Plant outdoors (fall) | Oct 10 – Nov 10 |
Where these dates come from
ZIP code 81502 is matched to the NOAA station Grand Junction 6Ese, CO, 3 km away, at 4,760 ft elevation (119 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Grand Junction 6Ese, CO (used) | 4,760 ft | Apr 23 | Oct 20 |
| Grand Junction Wfo, CO | 4,826 ft | Apr 14 | Oct 23 |
| Grand Junction Walker Fld, CO | 4,858 ft | Apr 28 | Oct 16 |
| Palisade, CO | 4,751 ft | Apr 17 | Oct 26 |
Frost dates near Grand Junction
- Grand Junction, CO 81503 · last Apr 23, first Oct 20
- Clifton, CO 81520 · last Apr 23, first Oct 20
- Whitewater, CO 81527 · last Apr 23, first Oct 20
- Palisade, CO 81526 · last Apr 17, first Oct 26
- Glade Park, CO 81523 · last May 21, first Sep 26
- Fruita, CO 81521 · last Apr 27, first Oct 11
- Mesa, CO 81643 · last May 17, first Sep 30
- Loma, CO 81524 · last Apr 27, first Oct 11
Frequently asked questions
- When is the last frost in Grand Junction, CO?
- For ZIP code 81502, the average last spring frost (32°F) is April 23, based on NOAA 1991-2020 climate normals for the Grand Junction 6Ese, CO weather station. There is a 1-in-10 chance of a frost after May 9.
- When is the first frost in Grand Junction, CO?
- The average first fall frost (32°F) is October 20. There is a 1-in-10 chance of frost by October 5, so tender plants are at risk from that point on.
- How long is the growing season in 81502?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 179 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.