Frost dates for 80733Hillrose, CO
The average last spring frost in Hillrose is May 6 and the average first fall frost is October 6, giving a typical growing season of about 153 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 6
- Average first fall frost
- Oct 6
- Growing season
- 153 days
Safer after May 19 (1-in-10 risk)
Possible by Sep 24 (1-in-10 risk)
Last frost typically in 191 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 4 · May 15 · May 29 | Sep 17 · Sep 28 · Oct 8 | 135 days | 100% |
| Frost / freeze (32°F) | Apr 23 · May 6 · May 19 | Sep 24 · Oct 6 · Oct 18 | 153 days | 100% |
| Hard freeze (28°F) | Apr 11 · Apr 27 · May 9 | Oct 2 · Oct 15 · Oct 26 | 171 days | 100% |
Planting calendar for Hillrose
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 5 – Jun 11 |
| Tomatoes | Transplant outdoors | May 22 – Jun 16 |
| Peppers | Start seeds indoors | Apr 5 – May 6 |
| Peppers | Transplant outdoors | Jun 5 – Jul 6 |
| Eggplant | Start seeds indoors | Apr 22 – May 21 |
| Eggplant | Transplant outdoors | Jun 5 – Jul 6 |
| Cucumbers | Sow outdoors | Jun 5 – Jun 26 |
| Summer squash | Sow outdoors | May 22 – Jul 6 |
| Winter squash & pumpkins | Sow outdoors | Jun 5 – Jul 6 |
| Snap beans | Sow outdoors | May 22 – Jul 19 |
| Sweet corn | Sow outdoors | May 22 – Jun 16 |
| Watermelon & cantaloupe | Sow outdoors | Jun 5 – Jul 6 |
| Okra | Sow outdoors | May 29 – Jun 21 |
| Peas | Sow outdoors (spring) | Apr 5 – May 21 |
| Potatoes | Plant outdoors (spring) | Apr 5 – Jun 5 |
| Onions | Start seeds indoors (spring) | Feb 22 – Mar 21 |
| Onions | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (spring) | Mar 18 – Apr 21 |
| Broccoli | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (fall) | Jun 6 – Jun 16 |
| Broccoli | Transplant outdoors (fall) | Jul 6 – Jul 17 |
| Cabbage | Start seeds indoors (spring) | Mar 8 – Apr 5 |
| Cabbage | Transplant outdoors (spring) | Apr 5 – May 6 |
| Cabbage | Start seeds indoors (fall) | May 27 – Jun 26 |
| Cabbage | Transplant outdoors (fall) | Jun 26 – Jul 27 |
| Leaf lettuce | Sow outdoors (spring) | Apr 5 – Jun 21 |
| Leaf lettuce | Sow outdoors (fall) | Jun 26 – Aug 12 |
| Spinach | Sow outdoors (spring) | Mar 29 – May 12 |
| Spinach | Sow outdoors (fall) | Jul 13 – Aug 17 |
| Radishes | Sow outdoors (spring) | Apr 5 – May 26 |
| Radishes | Sow outdoors (fall) | Jun 26 – Aug 27 |
| Kale | Sow outdoors (spring) | Apr 22 – May 12 |
| Kale | Sow outdoors (fall) | Jun 19 – Jul 27 |
| Carrots | Sow outdoors (spring) | May 6 – Jun 21 |
| Carrots | Sow outdoors (fall) | May 27 – Jul 12 |
| Garlic | Plant outdoors (fall) | Sep 26 – Oct 27 |
Where these dates come from
ZIP code 80733 is matched to the NOAA station Ft Morgan, CO, 32.4 km away, at 4,376 ft elevation (236 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Ft Morgan, CO (used) | 4,376 ft | May 6 | Oct 6 |
| Woodrow 6Nne, CO | 4,374 ft | May 15 | Oct 1 |
| Akron Washington Co Ap, CO | 4,663 ft | May 6 | Oct 8 |
| Akron 4 E, CO | 4,542 ft | May 8 | Oct 6 |
Frost dates near Hillrose
- Snyder, CO 80750 · last May 6, first Oct 6
- Brush, CO 80723 · last May 6, first Oct 6
- Merino, CO 80741 · last May 10, first Oct 6
- Atwood, CO 80722 · last Apr 30, first Oct 9
- Fort Morgan, CO 80701 · last May 6, first Oct 6
- Log Lane Village, CO 80705 · last May 6, first Oct 6
- Akron, CO 80720 · last May 6, first Oct 8
- Weldona, CO 80653 · last May 6, first Oct 6
Frequently asked questions
- When is the last frost in Hillrose, CO?
- For ZIP code 80733, the average last spring frost (32°F) is May 6, based on NOAA 1991-2020 climate normals for the Ft Morgan, CO weather station. There is a 1-in-10 chance of a frost after May 19.
- When is the first frost in Hillrose, CO?
- The average first fall frost (32°F) is October 6. There is a 1-in-10 chance of frost by September 24, so tender plants are at risk from that point on.
- How long is the growing season in 80733?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 153 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.