Frost dates for 59107Billings, MT
The average last spring frost in Billings is May 10 and the average first fall frost is October 1, giving a typical growing season of about 142 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 10
- Average first fall frost
- Oct 1
- Growing season
- 142 days
Safer after May 24 (1-in-10 risk)
Possible by Sep 19 (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 10 · May 24 · Jun 7 | Sep 7 · Sep 21 · Oct 3 | 118 days | 100% |
| Frost / freeze (32°F) | Apr 26 · May 10 · May 24 | Sep 19 · Oct 1 · Oct 15 | 142 days | 100% |
| Hard freeze (28°F) | Apr 10 · Apr 27 · May 10 | Sep 27 · Oct 12 · Oct 24 | 166 days | 100% |
Planting calendar for Billings
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 9 – Jun 15 |
| Tomatoes | Transplant outdoors | May 26 – Jun 11 |
| Peppers | Start seeds indoors | Apr 9 – May 10 |
| Peppers | Transplant outdoors | Jun 9 – Jul 10 |
| Eggplant | Start seeds indoors | Apr 26 – May 25 |
| Eggplant | Transplant outdoors | Jun 9 – Jul 10 |
| Cucumbers | Sow outdoors | Jun 9 – Jun 21 |
| Summer squash | Sow outdoors | May 26 – Jul 10 |
| Winter squash & pumpkins | Sow outdoors | Jun 9 – Jul 10 |
| Snap beans | Sow outdoors | May 26 – Jul 14 |
| Sweet corn | Sow outdoors | May 26 – Jun 11 |
| Watermelon & cantaloupe | Sow outdoors | Jun 9 – Jul 10 |
| Okra | Sow outdoors | Jun 2 – Jun 25 |
| Peas | Sow outdoors (spring) | Apr 9 – May 25 |
| Potatoes | Plant outdoors (spring) | Apr 9 – Jun 9 |
| Onions | Start seeds indoors (spring) | Feb 26 – Mar 25 |
| Onions | Transplant outdoors (spring) | Apr 26 – May 25 |
| Broccoli | Start seeds indoors (spring) | Mar 22 – Apr 25 |
| Broccoli | Transplant outdoors (spring) | Apr 26 – May 25 |
| Broccoli | Start seeds indoors (fall) | Jun 1 – Jun 11 |
| Broccoli | Transplant outdoors (fall) | Jul 1 – Jul 12 |
| Cabbage | Start seeds indoors (spring) | Mar 12 – Apr 9 |
| Cabbage | Transplant outdoors (spring) | Apr 9 – May 10 |
| Cabbage | Start seeds indoors (fall) | May 22 – Jun 21 |
| Cabbage | Transplant outdoors (fall) | Jun 21 – Jul 22 |
| Leaf lettuce | Sow outdoors (spring) | Apr 9 – Jun 25 |
| Leaf lettuce | Sow outdoors (fall) | Jun 21 – Aug 7 |
| Spinach | Sow outdoors (spring) | Apr 2 – May 16 |
| Spinach | Sow outdoors (fall) | Jul 8 – Aug 12 |
| Radishes | Sow outdoors (spring) | Apr 9 – May 30 |
| Radishes | Sow outdoors (fall) | Jun 21 – Aug 22 |
| Kale | Sow outdoors (spring) | Apr 26 – May 16 |
| Kale | Sow outdoors (fall) | Jun 14 – Jul 22 |
| Carrots | Sow outdoors (spring) | May 10 – Jun 25 |
| Carrots | Sow outdoors (fall) | May 22 – Jul 7 |
| Garlic | Plant outdoors (fall) | Sep 21 – Oct 22 |
Where these dates come from
ZIP code 59107 is matched to the NOAA station Billings Wtp, MT, 9 km away, at 3,097 ft elevation (56 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Billings Wtp, MT (used) | 3,097 ft | May 10 | Oct 1 |
| Billings Logan Intl Ap, MT | 3,581 ft | May 4 | Oct 7 |
| Huntley Exp Stn, MT | 3,034 ft | May 12 | Sep 25 |
| Billings Wfo, MT | 3,185 ft | May 5 | Oct 3 |
Frost dates near Billings
- Billings, MT 59103 · last May 10, first Oct 1
- Huntley, MT 59037 · last May 12, first Sep 25
- Shepherd, MT 59079 · last May 12, first Sep 25
- Worden, MT 59088 · last May 12, first Sep 25
- Ballantine, MT 59006 · last May 12, first Sep 25
- Acton, MT 59002 · last May 4, first Oct 7
- Laurel, MT 59044 · last May 5, first Oct 3
- Pompeys Pillar, MT 59064 · last May 12, first Sep 25
Frequently asked questions
- When is the last frost in Billings, MT?
- For ZIP code 59107, the average last spring frost (32°F) is May 10, based on NOAA 1991-2020 climate normals for the Billings Wtp, MT weather station. There is a 1-in-10 chance of a frost after May 24.
- When is the first frost in Billings, MT?
- The average first fall frost (32°F) is October 1. There is a 1-in-10 chance of frost by September 19, so tender plants are at risk from that point on.
- How long is the growing season in 59107?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 142 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.