In Billings, MT, the average last spring frost is May 4 and the average first fall frost is Oct 7, which leaves about 156 frost-free days for the garden. These dates come from NOAA climate normals for the Billings Logan International Airport, MT weather station, at 3,581 feet above sea level.
A moderate season leaves room for most vegetables. Start warm-season crops indoors for a head start, plant cool-season crops early and again in late summer, and keep row cover ready for surprise frosts. Frost timing varies from year to year: in about 1 spring in 10 the last frost falls as late as May 18, and in about 1 fall in 10 the first frost arrives as early as Sep 26.
Frost dates for Billings, MT
| Chance of a freeze (32°F) after or before this date | Last spring frost | First fall frost | Freeze-free season |
|---|---|---|---|
| Optimistic (about 1 year in 10) | Apr 20 | Oct 21 | 184 days |
| Average (half of years) | May 4 | Oct 7 | 156 days |
| Cautious (9 years in 10 are safe) | May 18 | Sep 26 | 131 days |
Source: NOAA NCEI U.S. Climate Normals, 1991 to 2020. Use the cautious dates for tender crops such as tomatoes and peppers.
When to plant in Billings, MT
These windows count weeks forward and back from the average frost dates above. They are planning guides: check the forecast before planting tender crops, and see our what to plant now tool for today's date.
| Crop | Start seeds indoors | Plant outdoors in spring | Plant in fall |
|---|---|---|---|
| Tomatoes | Mar 9 to Mar 23 | May 11 to May 18 | – |
| Peppers | Feb 23 to Mar 9 | May 18 to May 25 | – |
| Eggplant | Feb 23 to Mar 9 | May 18 to May 25 | – |
| Onions | Feb 23 to Mar 9 | Apr 6 to Apr 20 | – |
| Parsley | Feb 23 to Mar 9 | May 4 to May 11 | – |
| Broccoli, cabbage, cauliflower | Mar 9 to Mar 23 | Apr 20 to Apr 27 | Jul 15 to Aug 12 |
| Basil | Mar 23 to Mar 23 | May 11 to May 18 | – |
| Peas | Sow outdoors | Mar 23 to Apr 6 | Jul 15 to Aug 12 |
| Spinach | Sow outdoors | Mar 23 to Apr 6 | Aug 12 to Sep 9 |
| Radishes | Sow outdoors | Mar 23 to Apr 6 | Aug 12 to Sep 9 |
| Lettuce | Sow outdoors | Apr 6 to Apr 20 | Aug 12 to Sep 9 |
| Carrots | Sow outdoors | Apr 6 to Apr 20 | Jul 15 to Aug 12 |
| Beets | Sow outdoors | Apr 6 to Apr 20 | Jul 15 to Aug 12 |
| Potatoes | Sow outdoors | Apr 6 to Apr 20 | – |
| Kale | Sow outdoors | Apr 6 to Apr 20 | Jul 15 to Aug 12 |
| Swiss chard | Sow outdoors | Apr 20 to May 4 | – |
| Cilantro | Sow outdoors | Apr 20 to May 4 | Aug 12 to Sep 9 |
| Dill | Sow outdoors | May 4 to May 11 | – |
| Bush beans | Sow outdoors | May 11 to May 18 | Jul 4 to Jul 18 |
| Pole beans | Sow outdoors | May 11 to May 18 | – |
| Sweet corn | Sow outdoors | May 11 to May 18 | – |
| Cucumbers | Sow outdoors | May 11 to May 18 | Jun 24 to Jul 8 |
| Zucchini and summer squash | Sow outdoors | May 11 to May 18 | Jul 4 to Jul 18 |
| Winter squash | Sow outdoors | May 11 to May 18 | – |
| Sweet potatoes (slips) | Sow outdoors | May 18 to Jun 1 | – |
| Okra | Sow outdoors | May 18 to Jun 1 | – |
A dash in the fall column means the crop is not usually planted in fall, or the season is too short.
Overnight lows this week
The National Weather Service forecast shows frost risk on: Tue 17 night (34°F), Wed 18 night (27°F), Thu 19 night (29°F), Fri 20 night (28°F). Cover tender plants before dark on those nights.
| Night | Forecast low | Frost risk |
|---|---|---|
| Sun 15 night | 37°F | No frost expected |
| Sun 15 night | 37°F | No frost expected |
| Mon 16 night | 37°F | No frost expected |
| Tue 17 night | 34°F | Frost possible |
| Wed 18 night | 27°F | Freeze |
| Thu 19 night | 29°F | Freeze |
| Fri 20 night | 28°F | Freeze |
Live forecast for the station location, from the National Weather Service. For your own ZIP code, use our garden weather forecast.
More garden tools for Billings, MT
- Frost dates by ZIP code for your exact location
- What to plant now, based on today's date
- Garden weather forecast by ZIP code
- Safe transplant date calculator
Frequently asked questions
When is the last frost in Billings, MT?
The average last spring frost is May 4. A late frost as far out as May 18 happens in about 1 year in 10, so tender plants such as tomatoes and peppers are safest after that cautious date.
When is the first frost in Billings, MT?
The average first fall frost is Oct 7. It can arrive as early as Sep 26 in about 1 year in 10, so plan to harvest tender crops before then.
How long is the growing season in Billings, MT?
The average freeze-free season is about 156 days, between the average last spring frost and the average first fall frost.
Where do these dates come from?
They come from the NOAA 1991 to 2020 U.S. Climate Normals for the Billings Logan International Airport, MT station. Hills, valleys, lakes and city heat can shift frost by a week or more, so compare with neighbors who garden near you.