Frost Dates for Havre, MT 59501
Last spring frost May 15 · First fall frost September 19 · 127 frost-free days · USDA Zone 3b
ZIP 59501 has about 12,200 people.
Moderate season: 127 frost-free days. Spring frost risk spans May 1–May 30 (29 days). Fall frost risk spans September 6–September 29 (23 days).
Frost probability for 59501
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 30 | May 15 | May 1 |
| Fall (first frost) | September 6 | September 19 | September 29 |
Dates come from NOAA 1971–2000 freeze probabilities at FT ASSINIBOINE (22.0 km away); the 50% date is the median year.
Which crops fit a 127-day season in Havre
In Havre (127 frost-free days, a moderate season), 38 of 56 planner crops fit outright, 15 get two plantings, 2 need an indoor start, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Apr 10 | May 29–Jun 5 | 85 | fits: 80 days to maturity, 85 available after May 29. | — |
| Pepper | Apr 3 | May 29–Jun 5 | 85 | fits: 75 days to maturity, 85 available after May 29. | — |
| Lettuce | Mar 20 | Apr 17–Apr 24 | 162 | two-plantings: Plant Apr 17 and again by Jul 29; both mature before Sep 26. | Jul 29 |
| Carrots | — | Apr 24–May 1 | 169 | fits: 70 days to maturity, 169 available after Apr 24. | Jul 18 |
| Cucumber | Apr 24 | May 29–Jun 5 | 99 | fits: 60 days to maturity, 99 available after May 29. | Jun 23 |
| Beans | — | May 22–Jun 5 | 113 | fits: 60 days to maturity, 113 available after May 22. | Jun 30 |
| Peas | — | Mar 20–May 29 | 190 | fits: 65 days to maturity, 190 available after Mar 20. | Jul 9 |
| Zucchini | May 1 | May 29–Jun 5 | 99 | fits: 55 days to maturity, 99 available after May 29. | Jun 28 |
| Onion | Feb 20 | Apr 17–May 1 | 162 | fits: 100 days to maturity, 162 available after Apr 17. | — |
| Spinach | — | Mar 20–May 8 | 204 | two-plantings: Plant Mar 20 and again by Aug 17; both mature before Oct 10. | Aug 17 |
| Kale | Mar 6 | Apr 17–May 1 | 176 | two-plantings: Plant Apr 17 and again by Aug 2; both mature before Oct 10. | Aug 2 |
| Broccoli | Mar 20 | Apr 17–May 1 | 162 | fits: 80 days to maturity, 162 available after Apr 17. | Jun 24 |
| Cabbage | Mar 20 | Apr 17–May 1 | 176 | fits: 70 days to maturity, 176 available after Apr 17. | Jul 18 |
| Radish | — | Mar 20–Jun 12 | 190 | two-plantings: Plant Mar 20 and again by Aug 18; both mature before Sep 26. | Aug 18 |
| Beets | — | Mar 20–Jun 12 | 190 | two-plantings: Plant Mar 20 and again by Jul 19; both mature before Sep 26. | Jul 19 |
| Potatoes | — | May 1–May 8 | 148 | fits: 90 days to maturity, 148 available after May 1. | — |
| Garlic | — | Sep 19 | 232 | overwinter: Plant Sep 19 to Oct 10; harvest the following summer. | Oct 10 |
| Strawberry | — | Apr 10–Jun 5 | 183 | perennial: A perennial: plant Apr 10; it fruits from the following year and keeps producing for several years. | — |
| Corn | Apr 17 | May 22–May 29 | 99 | fits: 75 days to maturity, 99 available after May 22. | Jun 1 |
| Pumpkin | May 1 | May 29–May 29 | 92 | head-start: Even planted out May 29, the outdoor season is about 8 days short; choose an early variety or grow under cover. | — |
| Cauliflower | Apr 3 | May 8–May 22 | 141 | fits: 75 days to maturity, 141 available after May 8. | Jun 29 |
| Swiss Chard | Mar 20 | May 1–May 1 | 148 | two-plantings: Plant May 1 and again by Jul 19; both mature before Sep 26. | Jul 19 |
| Arugula | — | Mar 20–Jun 12 | 204 | two-plantings: Plant Mar 20 and again by Aug 17; both mature before Oct 10. | Aug 17 |
| Brussel Sprouts | Mar 20 | Apr 17–May 1 | 176 | fits: 100 days to maturity, 176 available after Apr 17. | Jun 18 |
| Butternut Squash | May 1 | May 29–Jun 5 | 92 | head-start: Even planted out May 29, the outdoor season is about 8 days short; choose an early variety or grow under cover. | — |
| Eggplant | Mar 27 | May 29–Jun 5 | 85 | fits: 70 days to maturity, 85 available after May 29. | May 30 |
| Okra | Apr 17 | May 22–May 29 | 106 | fits: 55 days to maturity, 106 available after May 22. | Jun 28 |
| Basil | Apr 10 | Jun 5–Jun 5 | 92 | fits: 60 days to maturity, 92 available after Jun 5. | Jun 23 |
| Cilantro | — | Apr 17–May 8 | 162 | two-plantings: Plant Apr 17 and again by Jul 24; both mature before Sep 26. | Jul 24 |
| Parsley | Mar 6 | May 22–May 29 | 127 | fits: 70 days to maturity, 127 available after May 22. | Jul 4 |
| Celery | Mar 6 | May 22–Jun 5 | 127 | fits: 120 days to maturity, 127 available after May 22. | — |
| Scallions | Mar 6 | Apr 17–May 1 | 176 | two-plantings: Plant Apr 17 and again by Jul 28; both mature before Oct 10. | Jul 28 |
| Turnip | — | Apr 17–May 1 | 176 | two-plantings: Plant Apr 17 and again by Aug 7; both mature before Oct 10. | Aug 7 |
| Kohlrabi | — | Apr 3–Apr 17 | 190 | two-plantings: Plant Apr 3 and again by Aug 2; both mature before Oct 10. | Aug 2 |
| Bok Choy | Apr 17 | May 8–May 15 | 141 | two-plantings: Plant May 8 and again by Jul 29; both mature before Sep 26. | Jul 29 |
| Collards | Mar 6 | Apr 17–May 1 | 176 | two-plantings: Plant Apr 17 and again by Jul 28; both mature before Oct 10. | Jul 28 |
| Cantaloupe | May 1 | May 29–Jun 5 | 85 | fits: 85 days to maturity, 85 available after May 29. | — |
| Chives | Feb 20 | May 22–May 29 | 141 | fits: 90 days to maturity, 141 available after May 22. | — |
| Dill | — | Mar 20–Jun 12 | 190 | two-plantings: Plant Mar 20 and again by Jul 19; both mature before Sep 26. | Jul 19 |
| Oregano | Mar 6 | May 22–May 29 | 141 | fits: 80 days to maturity, 141 available after May 22. | — |
| Rosemary | Feb 20 | May 22–May 29 | 127 | fits: 80 days to maturity, 127 available after May 22. | — |
| Sage | Mar 20 | May 22–May 29 | 141 | fits: 75 days to maturity, 141 available after May 22. | — |
| Thyme | Mar 6 | May 22–May 29 | 141 | fits: 90 days to maturity, 141 available after May 22. | — |
| Calendula | Apr 3 | May 1–May 15 | 148 | two-plantings: Plant May 1 and again by Jul 24; both mature before Sep 26. | Jul 24 |
| Cosmos | Apr 17 | May 15–May 29 | 113 | fits: 60 days to maturity, 113 available after May 15. | Jun 23 |
| Lavender | Feb 20 | May 15–May 29 | 148 | fits: 90 days to maturity, 148 available after May 15. | — |
| Marigolds | Apr 3 | May 15–May 22 | 113 | fits: 50 days to maturity, 113 available after May 15. | Jul 3 |
| Melons | May 1 | May 29–Jun 5 | 85 | fits: 85 days to maturity, 85 available after May 29. | — |
| Mint | — | May 15–May 29 | 148 | fits: 90 days to maturity, 148 available after May 15. | — |
| Nasturtiums | Apr 17 | May 15–May 22 | 113 | fits: 55 days to maturity, 113 available after May 15. | Jun 28 |
| Pole Beans | — | May 22–Jun 5 | 106 | fits: 65 days to maturity, 106 available after May 22. | Jun 18 |
| Spaghetti Squash | May 1 | May 29–Jun 5 | 92 | fits: 90 days to maturity, 92 available after May 29. | — |
| Sunflowers | — | May 15–May 29 | 113 | fits: 70 days to maturity, 113 available after May 15. | Jun 13 |
| Tomatillos | Mar 20 | May 22–May 29 | 92 | fits: 75 days to maturity, 92 available after May 22. | May 25 |
| Watermelon | May 1 | May 22–May 29 | 92 | fits: 80 days to maturity, 92 available after May 22. | — |
| Yellow Squash | May 1 | May 29–Jun 5 | 99 | fits: 55 days to maturity, 99 available after May 29. | Jun 28 |
| Zinnias | Apr 17 | May 15–May 29 | 113 | fits: 60 days to maturity, 113 available after May 15. | Jun 23 |
Month by month in Havre
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start indoors: Chives (Feb 20), Lavender (Feb 20), Onion (Feb 20), Rosemary (Feb 20). |
| March | Start indoors: Celery (Mar 6), Collards (Mar 6), Kale (Mar 6), Oregano (Mar 6), Parsley (Mar 6), Scallions (Mar 6), +9 more. Direct sow from: Arugula (Mar 20), Beets (Mar 20), Dill (Mar 20), Peas (Mar 20), Radish (Mar 20), Spinach (Mar 20). |
| April | Start indoors: Calendula (Apr 3), Cauliflower (Apr 3), Marigolds (Apr 3), Pepper (Apr 3), Basil (Apr 10), Tomato (Apr 10), +7 more. Direct sow from: Kohlrabi (Apr 3), Cilantro (Apr 17), Turnip (Apr 17), Carrots (Apr 24). Transplant from: Broccoli (Apr 17), Brussel Sprouts (Apr 17), Cabbage (Apr 17), Collards (Apr 17), Kale (Apr 17), Lettuce (Apr 17), +2 more. Plant: Strawberry (Apr 10). |
| May | Start indoors: Butternut Squash (May 1), Cantaloupe (May 1), Melons (May 1), Pumpkin (May 1), Spaghetti Squash (May 1), Watermelon (May 1), +2 more. Direct sow from: Potatoes (May 1), Sunflowers (May 15), Beans (May 22), Pole Beans (May 22). Transplant from: Calendula (May 1), Swiss Chard (May 1), Bok Choy (May 8), Cauliflower (May 8), Cosmos (May 15), Lavender (May 15), +26 more. Last frost around May 15. Last sowing dates: Tomatillos (May 25), Eggplant (May 30). |
| June | Transplant from: Basil (Jun 5). Last sowing dates: Corn (Jun 1), Sunflowers (Jun 13), Brussel Sprouts (Jun 18), Pole Beans (Jun 18), Basil (Jun 23), Cosmos (Jun 23), +9 more. |
| July | Last sowing dates: Marigolds (Jul 3), Parsley (Jul 4), Peas (Jul 9), Cabbage (Jul 18), Carrots (Jul 18), Beets (Jul 19), +8 more. |
| August | Last sowing dates: Kale (Aug 2), Kohlrabi (Aug 2), Turnip (Aug 7), Arugula (Aug 17), Spinach (Aug 17), Radish (Aug 18). |
| September | Direct sow from: Garlic (Sep 19). First frost around September 19. |
| October | Last sowing dates: Garlic (Oct 10). |
| November | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
| December | Clean up spent plants. Add compost to beds. Rest, review, and plan next year's garden. |
Frequently Asked Questions
What is the last frost date for Havre, MT (ZIP 59501)?
The median last spring frost date for Havre, MT (ZIP code 59501) is around May 15. This is the 50th-percentile date — meaning half of all years see frost end before this date. Use the 10% and 90% dates to understand the full range of risk in your area. One year in ten frost ends before May 1; one in ten it runs past May 30.
What is the first fall frost date in Havre, MT?
The median first fall frost date for Havre, MT is around September 19. Plan to harvest or protect frost-sensitive crops like tomatoes and peppers at least a week before this date to avoid losses. The first frost arrives around September 6 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Havre, MT?
The frost-free growing season in Havre is about 127 days. This window — from your last spring frost to your first fall frost — is when warm-season vegetables thrive. Cold-hardy crops like kale, spinach, and peas can extend your season by weeks on either side. In Havre (127 frost-free days, a moderate season), 38 of 56 planner crops fit outright, 15 get two plantings, 2 need an indoor start, 1 crop is perennial.
What USDA hardiness zone is Havre, MT?
Havre, MT is in USDA hardiness zone 3b (2023 USDA Plant Hardiness Zone Map). Zones come from the average coldest winter temperature, so they tell you which perennials survive the winter; the frost dates on this page tell you when to plant.
When should I start tomatoes indoors in Havre, MT?
Start tomatoes indoors Apr 10 and plant out May 29 in Havre. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Havre?
Two: plant Apr 17 and again by Jul 29; both mature before Sep 26.
When do I plant garlic in Havre?
Sep 19 to Oct 10; it overwinters and is ready the following summer.
Can I grow Butternut Squash in Havre?
Yes, with help. Even planted out May 29, the outdoor season is about 8 days short; choose an early variety or grow under cover.
Nearby and related
- Frost dates for Great Falls, MT 59404 (102.2 mi)
- Frost dates for Great Falls, MT 59405 (118.5 mi)
- Frost dates for Helena, MT 59601 (184.2 mi)
- Frost dates for Belgrade, MT 59714 (197.5 mi)
- Frost dates for Columbia Falls, MT 59912 (200.4 mi)
- When to plant in MT
- When to plant Peppers in MT
- When to plant Cucumbers in MT
- When to plant Zucchini in MT
- When to plant Butternut Squash in MT
- When to plant Basil in MT
- When to plant Sweet Corn in MT
- Look up another ZIP