Frost dates for 58847Keene, ND
The average last spring frost in Keene is May 20 and the average first fall frost is September 20, giving a typical growing season of about 121 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 20
- Average first fall frost
- Sep 20
- Growing season
- 121 days
Safer after Jun 2 (1-in-10 risk)
Possible by Sep 5 (1-in-10 risk)
Last frost typically in 198 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 17 · May 30 · Jun 20 | Aug 27 · Sep 11 · Sep 23 | 102 days | 100% |
| Frost / freeze (32°F) | May 8 · May 20 · Jun 2 | Sep 5 · Sep 20 · Oct 2 | 121 days | 100% |
| Hard freeze (28°F) | Apr 27 · May 10 · May 24 | Sep 13 · Sep 28 · Oct 14 | 141 days | 100% |
Planting calendar for Keene
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 19 – Jun 25 |
| Tomatoes | Transplant outdoors | Jun 5 – May 31 |
| Peppers | Start seeds indoors | Apr 19 – May 20 |
| Peppers | Transplant outdoors | Jun 19 – Jul 20 |
| Eggplant | Start seeds indoors | May 6 – Jun 4 |
| Eggplant | Transplant outdoors | Jun 19 – Jul 20 |
| Cucumbers | Sow outdoors | Jun 19 – Jun 10 |
| Summer squash | Sow outdoors | Jun 5 – Jul 20 |
| Winter squash & pumpkins | Sow outdoors | Jun 19 – Jul 20 |
| Snap beans | Sow outdoors | Jun 5 – Jul 3 |
| Sweet corn | Sow outdoors | Jun 5 – May 31 |
| Watermelon & cantaloupe | Sow outdoors | Jun 19 – Jul 20 |
| Okra | Sow outdoors | Jun 12 – Jul 5 |
| Peas | Sow outdoors (spring) | Apr 19 – Jun 4 |
| Potatoes | Plant outdoors (spring) | Apr 19 – Jun 19 |
| Onions | Start seeds indoors (spring) | Mar 8 – Apr 4 |
| Onions | Transplant outdoors (spring) | May 6 – Jun 4 |
| Broccoli | Start seeds indoors (spring) | Apr 1 – May 5 |
| Broccoli | Transplant outdoors (spring) | May 6 – Jun 4 |
| Broccoli | Start seeds indoors (fall) | May 21 – May 31 |
| Broccoli | Transplant outdoors (fall) | Jun 20 – Jul 1 |
| Cabbage | Start seeds indoors (spring) | Mar 22 – Apr 19 |
| Cabbage | Transplant outdoors (spring) | Apr 19 – May 20 |
| Cabbage | Start seeds indoors (fall) | May 11 – Jun 10 |
| Cabbage | Transplant outdoors (fall) | Jun 10 – Jul 11 |
| Leaf lettuce | Sow outdoors (spring) | Apr 19 – Jul 5 |
| Leaf lettuce | Sow outdoors (fall) | Jun 10 – Jul 27 |
| Spinach | Sow outdoors (spring) | Apr 12 – May 26 |
| Spinach | Sow outdoors (fall) | Jun 27 – Aug 1 |
| Radishes | Sow outdoors (spring) | Apr 19 – Jun 9 |
| Radishes | Sow outdoors (fall) | Jun 10 – Aug 11 |
| Kale | Sow outdoors (spring) | May 6 – May 26 |
| Kale | Sow outdoors (fall) | Jun 3 – Jul 11 |
| Carrots | Sow outdoors (spring) | May 20 – Jul 5 |
| Carrots | Sow outdoors (fall) | May 11 – Jun 26 |
| Garlic | Plant outdoors (fall) | Sep 10 – Oct 11 |
Where these dates come from
ZIP code 58847 is matched to the NOAA station Keene 3S, ND, 5.4 km away, at 2,470 ft elevation (36 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Keene 3S, ND (used) | 2,470 ft | May 20 | Sep 20 |
| Watford City, ND | 2,170 ft | May 9 | Sep 27 |
| Watford City 14S, ND | 2,027 ft | May 22 | Sep 17 |
| Tioga 1E, ND | 2,245 ft | May 11 | Sep 26 |
Frost dates near Keene
- Mandaree, ND 58757 · last May 20, first Sep 20
- Watford City, ND 58854 · last May 9, first Sep 27
- New Town, ND 58763 · last May 17, first Sep 23
- White Earth, ND 58794 · last May 11, first Sep 26
- Arnegard, ND 58835 · last May 9, first Sep 27
- Ray, ND 58849 · last May 11, first Sep 26
- Tioga, ND 58852 · last May 11, first Sep 26
- Ross, ND 58776 · last May 17, first Sep 23
Frequently asked questions
- When is the last frost in Keene, ND?
- For ZIP code 58847, the average last spring frost (32°F) is May 20, based on NOAA 1991-2020 climate normals for the Keene 3S, ND weather station. There is a 1-in-10 chance of a frost after June 2.
- When is the first frost in Keene, ND?
- The average first fall frost (32°F) is September 20. There is a 1-in-10 chance of frost by September 5, so tender plants are at risk from that point on.
- How long is the growing season in 58847?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 121 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.