Frost dates for 72170Ulm, AR
The average last spring frost in Ulm is March 11 and the average first fall frost is November 17, giving a typical growing season of about 250 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 11
- Average first fall frost
- Nov 17
- Growing season
- 250 days
Safer after Mar 31 (1-in-10 risk)
Possible by Oct 31 (1-in-10 risk)
First frost typically in 14 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) | Mar 4 · Mar 23 · Apr 9 | Oct 23 · Nov 5 · Nov 22 | 226 days | 100% |
| Frost / freeze (32°F) | Feb 21 · Mar 11 · Mar 31 | Oct 31 · Nov 17 · Dec 6 | 250 days | 100% |
| Hard freeze (28°F) | Feb 2 · Feb 28 · Mar 19 | Nov 8 · Dec 1 · Dec 30 | 276 days | 100% |
Planting calendar for Ulm
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 | Feb 8 – Apr 16 |
| Tomatoes | Transplant outdoors | Mar 27 – Jul 28 |
| Peppers | Start seeds indoors | Feb 8 – Mar 11 |
| Peppers | Transplant outdoors | Apr 10 – May 11 |
| Eggplant | Start seeds indoors | Feb 25 – Mar 26 |
| Eggplant | Transplant outdoors | Apr 10 – May 11 |
| Cucumbers | Sow outdoors | Apr 10 – Aug 7 |
| Summer squash | Sow outdoors | Mar 27 – May 11 |
| Winter squash & pumpkins | Sow outdoors | Apr 10 – May 11 |
| Snap beans | Sow outdoors | Mar 27 – Aug 30 |
| Sweet corn | Sow outdoors | Mar 27 – Jul 28 |
| Watermelon & cantaloupe | Sow outdoors | Apr 10 – May 11 |
| Okra | Sow outdoors | Apr 3 – Apr 26 |
| Peas | Sow outdoors (spring) | Feb 8 – Mar 26 |
| Potatoes | Plant outdoors (spring) | Feb 8 – Apr 10 |
| Onions | Start seeds indoors (spring) | Dec 28 – Jan 24 |
| Onions | Transplant outdoors (spring) | Feb 25 – Mar 26 |
| Broccoli | Start seeds indoors (spring) | Jan 21 – Feb 24 |
| Broccoli | Transplant outdoors (spring) | Feb 25 – Mar 26 |
| Broccoli | Start seeds indoors (fall) | Jul 18 – Jul 28 |
| Broccoli | Transplant outdoors (fall) | Aug 17 – Aug 28 |
| Cabbage | Start seeds indoors (spring) | Jan 11 – Feb 8 |
| Cabbage | Transplant outdoors (spring) | Feb 8 – Mar 11 |
| Cabbage | Start seeds indoors (fall) | Jul 8 – Aug 7 |
| Cabbage | Transplant outdoors (fall) | Aug 7 – Sep 7 |
| Leaf lettuce | Sow outdoors (spring) | Feb 8 – Apr 26 |
| Leaf lettuce | Sow outdoors (fall) | Aug 7 – Sep 23 |
| Spinach | Sow outdoors (spring) | Feb 1 – Mar 17 |
| Spinach | Sow outdoors (fall) | Aug 24 – Sep 28 |
| Radishes | Sow outdoors (spring) | Feb 8 – Mar 31 |
| Radishes | Sow outdoors (fall) | Aug 7 – Oct 8 |
| Kale | Sow outdoors (spring) | Feb 25 – Mar 17 |
| Kale | Sow outdoors (fall) | Jul 31 – Sep 7 |
| Carrots | Sow outdoors (spring) | Mar 11 – Apr 26 |
| Carrots | Sow outdoors (fall) | Jul 8 – Aug 23 |
| Garlic | Plant outdoors (fall) | Nov 7 – Dec 8 |
Where these dates come from
ZIP code 72170 is matched to the NOAA station Stuttgart 9 Ese, AR, 12.2 km away, at 198 ft elevation (12 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Stuttgart 9 Ese, AR (used) | 198 ft | Mar 11 | Nov 17 |
| Clarendon, AR | 179 ft | Mar 15 | Nov 11 |
| Saint Charles, AR | 200 ft | Mar 17 | Nov 10 |
| Brinkley, AR | 185 ft | Mar 18 | Nov 11 |
Frost dates near Ulm
- Roe, AR 72134 · last Mar 15, first Nov 11
- Stuttgart, AR 72160 · last Mar 11, first Nov 17
- Casscoe, AR 72026 · last Mar 11, first Nov 17
- Almyra, AR 72003 · last Mar 11, first Nov 17
- De Valls Bluff, AR 72041 · last Mar 15, first Nov 11
- Clarendon, AR 72029 · last Mar 15, first Nov 11
- Crocketts Bluff, AR 72038 · last Mar 11, first Nov 17
- Hazen, AR 72064 · last Mar 11, first Nov 14
Frequently asked questions
- When is the last frost in Ulm, AR?
- For ZIP code 72170, the average last spring frost (32°F) is March 11, based on NOAA 1991-2020 climate normals for the Stuttgart 9 Ese, AR weather station. There is a 1-in-10 chance of a frost after March 31.
- When is the first frost in Ulm, AR?
- The average first fall frost (32°F) is November 17. There is a 1-in-10 chance of frost by October 31, so tender plants are at risk from that point on.
- How long is the growing season in 72170?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 250 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.