Frost dates for 80741Merino, CO
The average last spring frost in Merino is May 10 and the average first fall frost is October 6, giving a typical growing season of about 147 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 10
- Average first fall frost
- Oct 6
- Growing season
- 147 days
Safer after May 22 (1-in-10 risk)
Possible by Sep 22 (1-in-10 risk)
Last frost typically in 188 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 8 · May 18 · May 31 | Sep 13 · Sep 27 · Oct 9 | 129 days | 100% |
| Frost / freeze (32°F) | Apr 28 · May 10 · May 22 | Sep 22 · Oct 6 · Oct 18 | 147 days | 100% |
| Hard freeze (28°F) | Apr 17 · Apr 30 · May 13 | Oct 2 · Oct 15 · Oct 26 | 165 days | 100% |
Planting calendar for Merino
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 16 |
| 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 26 |
| Summer squash | Sow outdoors | May 26 – Jul 10 |
| Winter squash & pumpkins | Sow outdoors | Jun 9 – Jul 10 |
| Snap beans | Sow outdoors | May 26 – Jul 19 |
| Sweet corn | Sow outdoors | May 26 – Jun 16 |
| 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 6 – Jun 16 |
| Broccoli | Transplant outdoors (fall) | Jul 6 – Jul 17 |
| Cabbage | Start seeds indoors (spring) | Mar 12 – Apr 9 |
| Cabbage | Transplant outdoors (spring) | Apr 9 – May 10 |
| Cabbage | Start seeds indoors (fall) | May 27 – Jun 26 |
| Cabbage | Transplant outdoors (fall) | Jun 26 – Jul 27 |
| Leaf lettuce | Sow outdoors (spring) | Apr 9 – Jun 25 |
| Leaf lettuce | Sow outdoors (fall) | Jun 26 – Aug 12 |
| Spinach | Sow outdoors (spring) | Apr 2 – May 16 |
| Spinach | Sow outdoors (fall) | Jul 13 – Aug 17 |
| Radishes | Sow outdoors (spring) | Apr 9 – May 30 |
| Radishes | Sow outdoors (fall) | Jun 26 – Aug 27 |
| Kale | Sow outdoors (spring) | Apr 26 – May 16 |
| Kale | Sow outdoors (fall) | Jun 19 – Jul 27 |
| Carrots | Sow outdoors (spring) | May 10 – Jun 25 |
| Carrots | Sow outdoors (fall) | May 27 – Jul 12 |
| Garlic | Plant outdoors (fall) | Sep 26 – Oct 27 |
Where these dates come from
ZIP code 80741 is matched to the NOAA station Leroy 5 Wsw, CO, 41.1 km away, at 4,467 ft elevation (74 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Leroy 5 Wsw, CO (used) | 4,467 ft | May 10 | Oct 6 |
| Sterling, CO | 3,974 ft | Apr 30 | Oct 9 |
| New Raymer, CO | 4,783 ft | May 9 | Oct 4 |
| Ft Morgan, CO | 4,376 ft | May 6 | Oct 6 |
Frost dates near Merino
- Atwood, CO 80722 · last Apr 30, first Oct 9
- Stoneham, CO 80754 · last May 9, first Oct 4
- Sterling, CO 80751 · last Apr 30, first Oct 9
- Hillrose, CO 80733 · last May 6, first Oct 6
- Snyder, CO 80750 · last May 6, first Oct 6
- New Raymer, CO 80742 · last May 9, first Oct 4
- Padroni, CO 80745 · last May 15, first Sep 30
- Brush, CO 80723 · last May 6, first Oct 6
Frequently asked questions
- When is the last frost in Merino, CO?
- For ZIP code 80741, the average last spring frost (32°F) is May 10, based on NOAA 1991-2020 climate normals for the Leroy 5 Wsw, CO weather station. There is a 1-in-10 chance of a frost after May 22.
- When is the first frost in Merino, CO?
- The average first fall frost (32°F) is October 6. There is a 1-in-10 chance of frost by September 22, so tender plants are at risk from that point on.
- How long is the growing season in 80741?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 147 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.