Frost dates for 80137Watkins, CO
The average last spring frost in Watkins is May 5 and the average first fall frost is October 9, giving a typical growing season of about 156 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 5
- Average first fall frost
- Oct 9
- Growing season
- 156 days
Safer after May 19 (1-in-10 risk)
Possible by Sep 27 (1-in-10 risk)
Last frost typically in 190 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 3 · May 16 · Jun 2 | Sep 19 · Oct 1 · Oct 12 | 136 days | 100% |
| Frost / freeze (32°F) | Apr 23 · May 5 · May 19 | Sep 27 · Oct 9 · Oct 20 | 156 days | 100% |
| Hard freeze (28°F) | Apr 10 · Apr 25 · May 9 | Oct 5 · Oct 18 · Oct 31 | 174 days | 100% |
Planting calendar for Watkins
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 4 – Jun 10 |
| Tomatoes | Transplant outdoors | May 21 – Jun 19 |
| Peppers | Start seeds indoors | Apr 4 – May 5 |
| Peppers | Transplant outdoors | Jun 4 – Jul 5 |
| Eggplant | Start seeds indoors | Apr 21 – May 20 |
| Eggplant | Transplant outdoors | Jun 4 – Jul 5 |
| Cucumbers | Sow outdoors | Jun 4 – Jun 29 |
| Summer squash | Sow outdoors | May 21 – Jul 5 |
| Winter squash & pumpkins | Sow outdoors | Jun 4 – Jul 5 |
| Snap beans | Sow outdoors | May 21 – Jul 22 |
| Sweet corn | Sow outdoors | May 21 – Jun 19 |
| Watermelon & cantaloupe | Sow outdoors | Jun 4 – Jul 5 |
| Okra | Sow outdoors | May 28 – Jun 20 |
| Peas | Sow outdoors (spring) | Apr 4 – May 20 |
| Potatoes | Plant outdoors (spring) | Apr 4 – Jun 4 |
| Onions | Start seeds indoors (spring) | Feb 21 – Mar 20 |
| Onions | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (spring) | Mar 17 – Apr 20 |
| Broccoli | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (fall) | Jun 9 – Jun 19 |
| Broccoli | Transplant outdoors (fall) | Jul 9 – Jul 20 |
| Cabbage | Start seeds indoors (spring) | Mar 7 – Apr 4 |
| Cabbage | Transplant outdoors (spring) | Apr 4 – May 5 |
| Cabbage | Start seeds indoors (fall) | May 30 – Jun 29 |
| Cabbage | Transplant outdoors (fall) | Jun 29 – Jul 30 |
| Leaf lettuce | Sow outdoors (spring) | Apr 4 – Jun 20 |
| Leaf lettuce | Sow outdoors (fall) | Jun 29 – Aug 15 |
| Spinach | Sow outdoors (spring) | Mar 28 – May 11 |
| Spinach | Sow outdoors (fall) | Jul 16 – Aug 20 |
| Radishes | Sow outdoors (spring) | Apr 4 – May 25 |
| Radishes | Sow outdoors (fall) | Jun 29 – Aug 30 |
| Kale | Sow outdoors (spring) | Apr 21 – May 11 |
| Kale | Sow outdoors (fall) | Jun 22 – Jul 30 |
| Carrots | Sow outdoors (spring) | May 5 – Jun 20 |
| Carrots | Sow outdoors (fall) | May 30 – Jul 15 |
| Garlic | Plant outdoors (fall) | Sep 29 – Oct 30 |
Where these dates come from
ZIP code 80137 is matched to the NOAA station Denver Intl Ap, CO, 10.1 km away, at 5,414 ft elevation (134 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Denver Intl Ap, CO (used) | 5,414 ft | May 5 | Oct 9 |
| Denver-Stapleton, CO | 5,286 ft | May 4 | Oct 8 |
| Cherry Creek Dam, CO | 5,647 ft | May 7 | Oct 8 |
| Brighton 3 Se, CO | 5,016 ft | May 3 | Oct 7 |
Frost dates near Watkins
- Aurora, CO 80019 · last May 5, first Oct 9
- Bennett, CO 80102 · last May 5, first Oct 9
- Denver, CO 80249 · last May 5, first Oct 9
- Brighton, CO 80601 · last May 3, first Oct 7
- Strasburg, CO 80136 · last May 13, first Oct 2
- Commerce City, CO 80022 · last May 4, first Oct 8
- Henderson, CO 80640 · last May 3, first Oct 7
- Dupont, CO 80024 · last May 4, first Oct 8
Frequently asked questions
- When is the last frost in Watkins, CO?
- For ZIP code 80137, the average last spring frost (32°F) is May 5, based on NOAA 1991-2020 climate normals for the Denver Intl Ap, CO weather station. There is a 1-in-10 chance of a frost after May 19.
- When is the first frost in Watkins, CO?
- The average first fall frost (32°F) is October 9. There is a 1-in-10 chance of frost by September 27, so tender plants are at risk from that point on.
- How long is the growing season in 80137?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 156 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.