Frost dates for 58266Niagara, ND
The average last spring frost in Niagara is May 11 and the average first fall frost is September 28, giving a typical growing season of about 138 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 11
- Average first fall frost
- Sep 28
- Growing season
- 138 days
Safer after May 25 (1-in-10 risk)
Possible by Sep 16 (1-in-10 risk)
Last frost typically in 197 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 9 · May 21 · Jun 2 | Sep 7 · Sep 20 · Oct 1 | 120 days | 100% |
| Frost / freeze (32°F) | Apr 29 · May 11 · May 25 | Sep 16 · Sep 28 · Oct 10 | 138 days | 100% |
| Hard freeze (28°F) | Apr 19 · May 2 · May 16 | Sep 25 · Oct 7 · Oct 21 | 156 days | 100% |
Planting calendar for Niagara
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 10 – Jun 16 |
| Tomatoes | Transplant outdoors | May 27 – Jun 8 |
| Peppers | Start seeds indoors | Apr 10 – May 11 |
| Peppers | Transplant outdoors | Jun 10 – Jul 11 |
| Eggplant | Start seeds indoors | Apr 27 – May 26 |
| Eggplant | Transplant outdoors | Jun 10 – Jul 11 |
| Cucumbers | Sow outdoors | Jun 10 – Jun 18 |
| Summer squash | Sow outdoors | May 27 – Jul 11 |
| Winter squash & pumpkins | Sow outdoors | Jun 10 – Jul 11 |
| Snap beans | Sow outdoors | May 27 – Jul 11 |
| Sweet corn | Sow outdoors | May 27 – Jun 8 |
| Watermelon & cantaloupe | Sow outdoors | Jun 10 – Jul 11 |
| Okra | Sow outdoors | Jun 3 – Jun 26 |
| Peas | Sow outdoors (spring) | Apr 10 – May 26 |
| Potatoes | Plant outdoors (spring) | Apr 10 – Jun 10 |
| Onions | Start seeds indoors (spring) | Feb 27 – Mar 26 |
| Onions | Transplant outdoors (spring) | Apr 27 – May 26 |
| Broccoli | Start seeds indoors (spring) | Mar 23 – Apr 26 |
| Broccoli | Transplant outdoors (spring) | Apr 27 – May 26 |
| Broccoli | Start seeds indoors (fall) | May 29 – Jun 8 |
| Broccoli | Transplant outdoors (fall) | Jun 28 – Jul 9 |
| Cabbage | Start seeds indoors (spring) | Mar 13 – Apr 10 |
| Cabbage | Transplant outdoors (spring) | Apr 10 – May 11 |
| Cabbage | Start seeds indoors (fall) | May 19 – Jun 18 |
| Cabbage | Transplant outdoors (fall) | Jun 18 – Jul 19 |
| Leaf lettuce | Sow outdoors (spring) | Apr 10 – Jun 26 |
| Leaf lettuce | Sow outdoors (fall) | Jun 18 – Aug 4 |
| Spinach | Sow outdoors (spring) | Apr 3 – May 17 |
| Spinach | Sow outdoors (fall) | Jul 5 – Aug 9 |
| Radishes | Sow outdoors (spring) | Apr 10 – May 31 |
| Radishes | Sow outdoors (fall) | Jun 18 – Aug 19 |
| Kale | Sow outdoors (spring) | Apr 27 – May 17 |
| Kale | Sow outdoors (fall) | Jun 11 – Jul 19 |
| Carrots | Sow outdoors (spring) | May 11 – Jun 26 |
| Carrots | Sow outdoors (fall) | May 19 – Jul 4 |
| Garlic | Plant outdoors (fall) | Sep 18 – Oct 19 |
Where these dates come from
ZIP code 58266 is matched to the NOAA station Petersburg 2 N, ND, 14.3 km away, at 1,532 ft elevation (148 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Petersburg 2 N, ND (used) | 1,532 ft | May 11 | Sep 28 |
| Larimore 4Sw, ND | 1,152 ft | May 11 | Sep 28 |
| Grand Forks Intl Ap, ND | 842 ft | May 16 | Sep 27 |
| Grand Forks Univ (Nws), ND | 830 ft | May 10 | Oct 1 |
Frost dates near Niagara
- Petersburg, ND 58272 · last May 11, first Sep 28
- Larimore, ND 58251 · last May 11, first Sep 28
- Dahlen, ND 58224 · last May 11, first Sep 28
- Michigan, ND 58259 · last May 11, first Sep 28
- Inkster, ND 58244 · last May 4, first Oct 7
- Fordville, ND 58231 · last May 11, first Sep 28
- Arvilla, ND 58214 · last May 16, first Sep 27
- Gilby, ND 58235 · last May 16, first Sep 27
Frequently asked questions
- When is the last frost in Niagara, ND?
- For ZIP code 58266, the average last spring frost (32°F) is May 11, based on NOAA 1991-2020 climate normals for the Petersburg 2 N, ND weather station. There is a 1-in-10 chance of a frost after May 25.
- When is the first frost in Niagara, ND?
- The average first fall frost (32°F) is September 28. There is a 1-in-10 chance of frost by September 16, so tender plants are at risk from that point on.
- How long is the growing season in 58266?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 138 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.