Frost dates for 81236Nathrop, CO
The average last spring frost in Nathrop is May 27 and the average first fall frost is September 23, giving a typical growing season of about 116 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 27
- Average first fall frost
- Sep 23
- Growing season
- 116 days
Safer after Jun 11 (1-in-10 risk)
Possible by Sep 10 (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) | May 26 · Jun 8 · Jun 21 | Aug 31 · Sep 13 · Sep 24 | 95 days | 100% |
| Frost / freeze (32°F) | May 13 · May 27 · Jun 11 | Sep 10 · Sep 23 · Oct 4 | 116 days | 100% |
| Hard freeze (28°F) | May 1 · May 15 · Jun 1 | Sep 19 · Oct 2 · Oct 15 | 138 days | 100% |
Planting calendar for Nathrop
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 26 – Jul 2 |
| Tomatoes | Transplant outdoors | Jun 12 – Jun 3 |
| Peppers | Start seeds indoors | Apr 26 – May 27 |
| Peppers | Transplant outdoors | Jun 26 – Jul 27 |
| Eggplant | Start seeds indoors | May 13 – Jun 11 |
| Eggplant | Transplant outdoors | Jun 26 – Jul 27 |
| Cucumbers | Sow outdoors | Jun 26 – Jun 13 |
| Summer squash | Sow outdoors | Jun 12 – Jul 27 |
| Winter squash & pumpkins | Sow outdoors | Jun 26 – Jul 27 |
| Snap beans | Sow outdoors | Jun 12 – Jul 6 |
| Sweet corn | Sow outdoors | Jun 12 – Jun 3 |
| Watermelon & cantaloupe | Sow outdoors | Jun 26 – Jul 27 |
| Okra | Sow outdoors | Jun 19 – Jul 12 |
| Peas | Sow outdoors (spring) | Apr 26 – Jun 11 |
| Potatoes | Plant outdoors (spring) | Apr 26 – Jun 26 |
| Onions | Start seeds indoors (spring) | Mar 15 – Apr 11 |
| Onions | Transplant outdoors (spring) | May 13 – Jun 11 |
| Broccoli | Start seeds indoors (spring) | Apr 8 – May 12 |
| Broccoli | Transplant outdoors (spring) | May 13 – Jun 11 |
| Broccoli | Start seeds indoors (fall) | May 24 – Jun 3 |
| Broccoli | Transplant outdoors (fall) | Jun 23 – Jul 4 |
| Cabbage | Start seeds indoors (spring) | Mar 29 – Apr 26 |
| Cabbage | Transplant outdoors (spring) | Apr 26 – May 27 |
| Cabbage | Start seeds indoors (fall) | May 14 – Jun 13 |
| Cabbage | Transplant outdoors (fall) | Jun 13 – Jul 14 |
| Leaf lettuce | Sow outdoors (spring) | Apr 26 – Jul 12 |
| Leaf lettuce | Sow outdoors (fall) | Jun 13 – Jul 30 |
| Spinach | Sow outdoors (spring) | Apr 19 – Jun 2 |
| Spinach | Sow outdoors (fall) | Jun 30 – Aug 4 |
| Radishes | Sow outdoors (spring) | Apr 26 – Jun 16 |
| Radishes | Sow outdoors (fall) | Jun 13 – Aug 14 |
| Kale | Sow outdoors (spring) | May 13 – Jun 2 |
| Kale | Sow outdoors (fall) | Jun 6 – Jul 14 |
| Carrots | Sow outdoors (spring) | May 27 – Jul 12 |
| Carrots | Sow outdoors (fall) | May 14 – Jun 29 |
| Garlic | Plant outdoors (fall) | Sep 13 – Oct 14 |
Where these dates come from
ZIP code 81236 is matched to the NOAA station Buena Vista 2S, CO, 12.8 km away, at 7,954 ft elevation (94 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Buena Vista 2S, CO (used) | 7,954 ft | May 27 | Sep 23 |
| Salida, CO | 7,160 ft | May 29 | Sep 20 |
| Antero Rsvr, CO | 8,939 ft | — | — |
| Sargents, CO | 8,460 ft | — | — |
Frost dates near Nathrop
- Buena Vista, CO 81211 · last May 27, first Sep 23
- Poncha Springs, CO 81242 · last May 29, first Sep 20
- Salida, CO 81201 · last May 29, first Sep 20
- Monarch, CO 81227 · last Jun 20, first Sep 8
- Hartsel, CO 80449 · last —, first —
- Pitkin, CO 81241 · last Jun 20, first Sep 8
- Granite, CO 81228 · last Jun 16, first Sep 10
- Sargents, CO 81248 · last —, first —
Frequently asked questions
- When is the last frost in Nathrop, CO?
- For ZIP code 81236, the average last spring frost (32°F) is May 27, based on NOAA 1991-2020 climate normals for the Buena Vista 2S, CO weather station. There is a 1-in-10 chance of a frost after June 11.
- When is the first frost in Nathrop, CO?
- The average first fall frost (32°F) is September 23. There is a 1-in-10 chance of frost by September 10, so tender plants are at risk from that point on.
- How long is the growing season in 81236?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 116 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.