Frost Dates for Missoula, MT 59802
Missoula has 6 ZIP codes. The Missoula, MT frost page lists all of them with their dates.
Last spring frost May 26 · First fall frost September 18 · 115 frost-free days · USDA Zone 5b
ZIP 59802 has about 19,900 people, one of 6 ZIP codes in Missoula.
Short season: 115 frost-free days. Spring frost risk spans May 6–June 15 (40 days). Fall frost risk spans September 4–October 2 (28 days).
Frost probability for 59802
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | June 15 | May 26 | May 6 |
| Fall (first frost) | September 4 | September 18 | October 2 |
Dates come from NOAA 1971–2000 freeze probabilities at MISSOULA INTL AP (13.3 km away); the 50% date is the median year.
Which crops fit a 115-day season in Missoula
In Missoula (115 frost-free days, a short season), 32 of 56 planner crops fit outright, 15 get two plantings, 8 need an indoor start, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Apr 21 | Jun 9–Jun 16 | 73 | head-start: Even planted out Jun 9, the outdoor season is about 7 days short; choose an early variety or grow under cover. | — |
| Pepper | Apr 14 | Jun 9–Jun 16 | 73 | head-start: Even planted out Jun 9, the outdoor season is about 2 days short; choose an early variety or grow under cover. | — |
| Lettuce | Mar 31 | Apr 28–May 5 | 150 | two-plantings: Plant Apr 28 and again by Jul 28; both mature before Sep 25. | Jul 28 |
| Carrots | — | May 5–May 12 | 157 | fits: 70 days to maturity, 157 available after May 5. | Jul 17 |
| Cucumber | May 5 | Jun 9–Jun 16 | 87 | fits: 60 days to maturity, 87 available after Jun 9. | Jun 22 |
| Beans | — | Jun 2–Jun 16 | 101 | fits: 60 days to maturity, 101 available after Jun 2. | Jun 29 |
| Peas | — | Mar 31–Jun 9 | 178 | fits: 65 days to maturity, 178 available after Mar 31. | Jul 8 |
| Zucchini | May 12 | Jun 9–Jun 16 | 87 | fits: 55 days to maturity, 87 available after Jun 9. | Jun 27 |
| Onion | Mar 3 | Apr 28–May 12 | 150 | fits: 100 days to maturity, 150 available after Apr 28. | — |
| Spinach | — | Mar 31–May 19 | 192 | two-plantings: Plant Mar 31 and again by Aug 16; both mature before Oct 9. | Aug 16 |
| Kale | Mar 17 | Apr 28–May 12 | 164 | two-plantings: Plant Apr 28 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Broccoli | Mar 31 | Apr 28–May 12 | 150 | fits: 80 days to maturity, 150 available after Apr 28. | Jun 23 |
| Cabbage | Mar 31 | Apr 28–May 12 | 164 | fits: 70 days to maturity, 164 available after Apr 28. | Jul 17 |
| Radish | — | Mar 31–Jun 23 | 178 | two-plantings: Plant Mar 31 and again by Aug 17; both mature before Sep 25. | Aug 17 |
| Beets | — | Mar 31–Jun 23 | 178 | two-plantings: Plant Mar 31 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Potatoes | — | May 12–May 19 | 136 | fits: 90 days to maturity, 136 available after May 12. | — |
| Garlic | — | Sep 18 | 220 | overwinter: Plant Sep 18 to Oct 9; harvest the following summer. | Oct 9 |
| Strawberry | — | Apr 21–Jun 16 | 171 | perennial: A perennial: plant Apr 21; it fruits from the following year and keeps producing for several years. | — |
| Corn | Apr 28 | Jun 2–Jun 9 | 87 | fits: 75 days to maturity, 87 available after Jun 2. | — |
| Pumpkin | May 12 | Jun 9–Jun 9 | 80 | head-start: Even planted out Jun 9, the outdoor season is about 20 days short; choose an early variety or grow under cover. | — |
| Cauliflower | Apr 14 | May 19–Jun 2 | 129 | fits: 75 days to maturity, 129 available after May 19. | Jun 28 |
| Swiss Chard | Mar 31 | May 12–May 12 | 136 | two-plantings: Plant May 12 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Arugula | — | Mar 31–Jun 23 | 192 | two-plantings: Plant Mar 31 and again by Aug 16; both mature before Oct 9. | Aug 16 |
| Brussel Sprouts | Mar 31 | Apr 28–May 12 | 164 | fits: 100 days to maturity, 164 available after Apr 28. | Jun 17 |
| Butternut Squash | May 12 | Jun 9–Jun 16 | 80 | head-start: Even planted out Jun 9, the outdoor season is about 20 days short; choose an early variety or grow under cover. | — |
| Eggplant | Apr 7 | Jun 9–Jun 16 | 73 | fits: 70 days to maturity, 73 available after Jun 9. | — |
| Okra | Apr 28 | Jun 2–Jun 9 | 94 | fits: 55 days to maturity, 94 available after Jun 2. | Jun 27 |
| Basil | Apr 21 | Jun 16–Jun 16 | 80 | fits: 60 days to maturity, 80 available after Jun 16. | Jun 22 |
| Cilantro | — | Apr 28–May 19 | 150 | two-plantings: Plant Apr 28 and again by Jul 23; both mature before Sep 25. | Jul 23 |
| Parsley | Mar 17 | Jun 2–Jun 9 | 115 | fits: 70 days to maturity, 115 available after Jun 2. | Jul 3 |
| Celery | Mar 17 | Jun 2–Jun 16 | 115 | head-start: Even planted out Jun 2, the outdoor season is about 5 days short; choose an early variety or grow under cover. | — |
| Scallions | Mar 17 | Apr 28–May 12 | 164 | two-plantings: Plant Apr 28 and again by Jul 27; both mature before Oct 9. | Jul 27 |
| Turnip | — | Apr 28–May 12 | 164 | two-plantings: Plant Apr 28 and again by Aug 6; both mature before Oct 9. | Aug 6 |
| Kohlrabi | — | Apr 14–Apr 28 | 178 | two-plantings: Plant Apr 14 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Bok Choy | Apr 28 | May 19–May 26 | 129 | two-plantings: Plant May 19 and again by Jul 28; both mature before Sep 25. | Jul 28 |
| Collards | Mar 17 | Apr 28–May 12 | 164 | two-plantings: Plant Apr 28 and again by Jul 27; both mature before Oct 9. | Jul 27 |
| Cantaloupe | May 12 | Jun 9–Jun 16 | 73 | head-start: Even planted out Jun 9, the outdoor season is about 12 days short; choose an early variety or grow under cover. | — |
| Chives | Mar 3 | Jun 2–Jun 9 | 129 | fits: 90 days to maturity, 129 available after Jun 2. | — |
| Dill | — | Mar 31–Jun 23 | 178 | two-plantings: Plant Mar 31 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Oregano | Mar 17 | Jun 2–Jun 9 | 129 | fits: 80 days to maturity, 129 available after Jun 2. | — |
| Rosemary | Mar 3 | Jun 2–Jun 9 | 115 | fits: 80 days to maturity, 115 available after Jun 2. | — |
| Sage | Mar 31 | Jun 2–Jun 9 | 129 | fits: 75 days to maturity, 129 available after Jun 2. | — |
| Thyme | Mar 17 | Jun 2–Jun 9 | 129 | fits: 90 days to maturity, 129 available after Jun 2. | — |
| Calendula | Apr 14 | May 12–May 26 | 136 | two-plantings: Plant May 12 and again by Jul 23; both mature before Sep 25. | Jul 23 |
| Cosmos | Apr 28 | May 26–Jun 9 | 101 | fits: 60 days to maturity, 101 available after May 26. | Jun 22 |
| Lavender | Mar 3 | May 26–Jun 9 | 136 | fits: 90 days to maturity, 136 available after May 26. | — |
| Marigolds | Apr 14 | May 26–Jun 2 | 101 | fits: 50 days to maturity, 101 available after May 26. | Jul 2 |
| Melons | May 12 | Jun 9–Jun 16 | 73 | head-start: Even planted out Jun 9, the outdoor season is about 12 days short; choose an early variety or grow under cover. | — |
| Mint | — | May 26–Jun 9 | 136 | fits: 90 days to maturity, 136 available after May 26. | — |
| Nasturtiums | Apr 28 | May 26–Jun 2 | 101 | fits: 55 days to maturity, 101 available after May 26. | Jun 27 |
| Pole Beans | — | Jun 2–Jun 16 | 94 | fits: 65 days to maturity, 94 available after Jun 2. | Jun 17 |
| Spaghetti Squash | May 12 | Jun 9–Jun 16 | 80 | head-start: Even planted out Jun 9, the outdoor season is about 10 days short; choose an early variety or grow under cover. | — |
| Sunflowers | — | May 26–Jun 9 | 101 | fits: 70 days to maturity, 101 available after May 26. | Jun 12 |
| Tomatillos | Mar 31 | Jun 2–Jun 9 | 80 | fits: 75 days to maturity, 80 available after Jun 2. | — |
| Watermelon | May 12 | Jun 2–Jun 9 | 80 | fits: 80 days to maturity, 80 available after Jun 2. | — |
| Yellow Squash | May 12 | Jun 9–Jun 16 | 87 | fits: 55 days to maturity, 87 available after Jun 9. | Jun 27 |
| Zinnias | Apr 28 | May 26–Jun 9 | 101 | fits: 60 days to maturity, 101 available after May 26. | Jun 22 |
Month by month in Missoula
| Month | What to do |
|---|---|
| January | Plan your garden layout and order seeds. Research varieties suited to your frost dates. |
| February | Start the slowest-growing crops indoors: onions, leeks, and celery (10–12 weeks before last frost). |
| March | Start indoors: Chives (Mar 3), Lavender (Mar 3), Onion (Mar 3), Rosemary (Mar 3), Celery (Mar 17), Collards (Mar 17), +12 more. Direct sow from: Arugula (Mar 31), Beets (Mar 31), Dill (Mar 31), Peas (Mar 31), Radish (Mar 31), Spinach (Mar 31). |
| April | Start indoors: Eggplant (Apr 7), Calendula (Apr 14), Cauliflower (Apr 14), Marigolds (Apr 14), Pepper (Apr 14), Basil (Apr 21), +7 more. Direct sow from: Kohlrabi (Apr 14), Cilantro (Apr 28), Turnip (Apr 28). Transplant from: Broccoli (Apr 28), Brussel Sprouts (Apr 28), Cabbage (Apr 28), Collards (Apr 28), Kale (Apr 28), Lettuce (Apr 28), +2 more. Plant: Strawberry (Apr 21). |
| May | Start indoors: Cucumber (May 5), Butternut Squash (May 12), Cantaloupe (May 12), Melons (May 12), Pumpkin (May 12), Spaghetti Squash (May 12), +3 more. Direct sow from: Carrots (May 5), Potatoes (May 12), Sunflowers (May 26). Transplant from: Calendula (May 12), Swiss Chard (May 12), Bok Choy (May 19), Cauliflower (May 19), Cosmos (May 26), Lavender (May 26), +4 more. Last frost around May 26. |
| June | Direct sow from: Beans (Jun 2), Pole Beans (Jun 2). Transplant from: Celery (Jun 2), Chives (Jun 2), Corn (Jun 2), Okra (Jun 2), Oregano (Jun 2), Parsley (Jun 2), +17 more. Last sowing dates: Sunflowers (Jun 12), Brussel Sprouts (Jun 17), Pole Beans (Jun 17), Basil (Jun 22), Cosmos (Jun 22), Cucumber (Jun 22), +8 more. |
| July | Last sowing dates: Marigolds (Jul 2), Parsley (Jul 3), Peas (Jul 8), Cabbage (Jul 17), Carrots (Jul 17), Beets (Jul 18), +8 more. |
| August | Last sowing dates: Kale (Aug 1), Kohlrabi (Aug 1), Turnip (Aug 6), Arugula (Aug 16), Spinach (Aug 16), Radish (Aug 17). |
| September | Direct sow from: Garlic (Sep 18). First frost around September 18. |
| October | Last sowing dates: Garlic (Oct 9). |
| 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 Missoula, MT (ZIP 59802)?
The median last spring frost date for Missoula, MT (ZIP code 59802) is around May 26. 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 6; one in ten it runs past June 15.
What is the first fall frost date in Missoula, MT?
The median first fall frost date for Missoula, MT is around September 18. 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 4 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Missoula, MT?
The frost-free growing season in Missoula is about 115 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 Missoula (115 frost-free days, a short season), 32 of 56 planner crops fit outright, 15 get two plantings, 8 need an indoor start, 1 crop is perennial.
What USDA hardiness zone is Missoula, MT?
Missoula, MT is in USDA hardiness zone 5b (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 Missoula, MT?
Start tomatoes indoors Apr 21 and plant out Jun 9 in Missoula. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Missoula?
Two: plant Apr 28 and again by Jul 28; both mature before Sep 25.
When do I plant garlic in Missoula?
Sep 18 to Oct 9; it overwinters and is ready the following summer.
Can I grow Celery in Missoula?
Yes, with help. Even planted out Jun 2, the outdoor season is about 5 days short; choose an early variety or grow under cover.
Which nearby ZIP has a longer season?
Polson (ZIP 59860) has 144 frost-free days, 29 more than Missoula (ZIP 59802). See Polson ZIP 59860 frost dates
Nearby and related
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- Frost dates for Hamilton, MT 59840 (51.2 mi)
- Frost dates for Polson, MT 59860 (57 mi)
- When to plant in MT
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