Frost dates for 80732Hereford, CO
The average last spring frost in Hereford is May 16 and the average first fall frost is September 27, giving a typical growing season of about 132 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 16
- Average first fall frost
- Sep 27
- Growing season
- 132 days
Safer after Jun 1 (1-in-10 risk)
Possible by Sep 13 (1-in-10 risk)
Last frost typically in 196 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 16 · May 30 · Jun 13 | Sep 4 · Sep 18 · Sep 29 | 111 days | 100% |
| Frost / freeze (32°F) | May 5 · May 16 · Jun 1 | Sep 13 · Sep 27 · Oct 7 | 132 days | 100% |
| Hard freeze (28°F) | Apr 25 · May 6 · May 18 | Sep 22 · Oct 4 · Oct 18 | 149 days | 100% |
Planting calendar for Hereford
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 15 – Jun 21 |
| Tomatoes | Transplant outdoors | Jun 1 – Jun 7 |
| Peppers | Start seeds indoors | Apr 15 – May 16 |
| Peppers | Transplant outdoors | Jun 15 – Jul 16 |
| Eggplant | Start seeds indoors | May 2 – May 31 |
| Eggplant | Transplant outdoors | Jun 15 – Jul 16 |
| Cucumbers | Sow outdoors | Jun 15 – Jun 17 |
| Summer squash | Sow outdoors | Jun 1 – Jul 16 |
| Winter squash & pumpkins | Sow outdoors | Jun 15 – Jul 16 |
| Snap beans | Sow outdoors | Jun 1 – Jul 10 |
| Sweet corn | Sow outdoors | Jun 1 – Jun 7 |
| Watermelon & cantaloupe | Sow outdoors | Jun 15 – Jul 16 |
| Okra | Sow outdoors | Jun 8 – Jul 1 |
| Peas | Sow outdoors (spring) | Apr 15 – May 31 |
| Potatoes | Plant outdoors (spring) | Apr 15 – Jun 15 |
| Onions | Start seeds indoors (spring) | Mar 4 – Mar 31 |
| Onions | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (spring) | Mar 28 – May 1 |
| Broccoli | Transplant outdoors (spring) | May 2 – May 31 |
| Broccoli | Start seeds indoors (fall) | May 28 – Jun 7 |
| Broccoli | Transplant outdoors (fall) | Jun 27 – Jul 8 |
| Cabbage | Start seeds indoors (spring) | Mar 18 – Apr 15 |
| Cabbage | Transplant outdoors (spring) | Apr 15 – May 16 |
| Cabbage | Start seeds indoors (fall) | May 18 – Jun 17 |
| Cabbage | Transplant outdoors (fall) | Jun 17 – Jul 18 |
| Leaf lettuce | Sow outdoors (spring) | Apr 15 – Jul 1 |
| Leaf lettuce | Sow outdoors (fall) | Jun 17 – Aug 3 |
| Spinach | Sow outdoors (spring) | Apr 8 – May 22 |
| Spinach | Sow outdoors (fall) | Jul 4 – Aug 8 |
| Radishes | Sow outdoors (spring) | Apr 15 – Jun 5 |
| Radishes | Sow outdoors (fall) | Jun 17 – Aug 18 |
| Kale | Sow outdoors (spring) | May 2 – May 22 |
| Kale | Sow outdoors (fall) | Jun 10 – Jul 18 |
| Carrots | Sow outdoors (spring) | May 16 – Jul 1 |
| Carrots | Sow outdoors (fall) | May 18 – Jul 3 |
| Garlic | Plant outdoors (fall) | Sep 17 – Oct 18 |
Where these dates come from
ZIP code 80732 is matched to the NOAA station Pine Bluffs 5W, WY, 25.1 km away, at 5,180 ft elevation (102 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Pine Bluffs 5W, WY (used) | 5,180 ft | May 16 | Sep 27 |
| Carpenter 3N, WY | 5,437 ft | May 14 | Sep 26 |
| Pine Bluffs 1Ese, WY | 5,058 ft | May 10 | Oct 1 |
| Archer, WY | 6,010 ft | May 21 | Sep 24 |
Frost dates near Hereford
- Carpenter, WY 82054 · last May 16, first Sep 27
- Grover, CO 80729 · last May 18, first Sep 29
- Burns, WY 82053 · last May 16, first Sep 27
- Pine Bluffs, WY 82082 · last May 16, first Sep 27
- Hillsdale, WY 82060 · last May 14, first Sep 26
- Briggsdale, CO 80611 · last May 12, first Sep 28
- Cheyenne, WY 82003 · last May 14, first Oct 1
- Bushnell, NE 69128 · last May 15, first Sep 26
Frequently asked questions
- When is the last frost in Hereford, CO?
- For ZIP code 80732, the average last spring frost (32°F) is May 16, based on NOAA 1991-2020 climate normals for the Pine Bluffs 5W, WY weather station. There is a 1-in-10 chance of a frost after June 1.
- When is the first frost in Hereford, CO?
- The average first fall frost (32°F) is September 27. There is a 1-in-10 chance of frost by September 13, so tender plants are at risk from that point on.
- How long is the growing season in 80732?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 132 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.