Frost Dates for Idaho Falls, ID 83404
Idaho Falls has 4 ZIP codes. The Idaho Falls, ID frost page lists all of them with their dates.
Last spring frost May 28 · First fall frost September 18 · 113 frost-free days · USDA Zone 5b
ZIP 83404 has about 27,500 people, one of 4 ZIP codes in Idaho Falls.
Short season: 113 frost-free days. Spring frost risk spans May 10–June 16 (37 days). Fall frost risk spans September 2–October 2 (30 days).
Frost probability for 83404
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | June 16 | May 28 | May 10 |
| Fall (first frost) | September 2 | September 18 | October 2 |
Dates come from NOAA 1971–2000 freeze probabilities at BLACKFOOT FIRE DEPT (37.5 km away); the 50% date is the median year.
Which crops fit a 113-day season in Idaho Falls
In Idaho Falls (113 frost-free days, a short season), 31 of 56 planner crops fit outright, 15 get two plantings, 7 need an indoor start, 2 don't reliably mature, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Apr 23 | Jun 11–Jun 18 | 71 | head-start: Even planted out Jun 11, the outdoor season is about 9 days short; choose an early variety or grow under cover. | — |
| Pepper | Apr 16 | Jun 11–Jun 18 | 71 | head-start: Even planted out Jun 11, the outdoor season is about 4 days short; choose an early variety or grow under cover. | — |
| Lettuce | Apr 2 | Apr 30–May 7 | 148 | two-plantings: Plant Apr 30 and again by Jul 28; both mature before Sep 25. | Jul 28 |
| Carrots | — | May 7–May 14 | 155 | fits: 70 days to maturity, 155 available after May 7. | Jul 17 |
| Cucumber | May 7 | Jun 11–Jun 18 | 85 | fits: 60 days to maturity, 85 available after Jun 11. | Jun 22 |
| Beans | — | Jun 4–Jun 18 | 99 | fits: 60 days to maturity, 99 available after Jun 4. | Jun 29 |
| Peas | — | Apr 2–Jun 11 | 176 | fits: 65 days to maturity, 176 available after Apr 2. | Jul 8 |
| Zucchini | May 14 | Jun 11–Jun 18 | 85 | fits: 55 days to maturity, 85 available after Jun 11. | Jun 27 |
| Onion | Mar 5 | Apr 30–May 14 | 148 | fits: 100 days to maturity, 148 available after Apr 30. | — |
| Spinach | — | Apr 2–May 21 | 190 | two-plantings: Plant Apr 2 and again by Aug 16; both mature before Oct 9. | Aug 16 |
| Kale | Mar 19 | Apr 30–May 14 | 162 | two-plantings: Plant Apr 30 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Broccoli | Apr 2 | Apr 30–May 14 | 148 | fits: 80 days to maturity, 148 available after Apr 30. | Jun 23 |
| Cabbage | Apr 2 | Apr 30–May 14 | 162 | fits: 70 days to maturity, 162 available after Apr 30. | Jul 17 |
| Radish | — | Apr 2–Jun 25 | 176 | two-plantings: Plant Apr 2 and again by Aug 17; both mature before Sep 25. | Aug 17 |
| Beets | — | Apr 2–Jun 25 | 176 | two-plantings: Plant Apr 2 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Potatoes | — | May 14–May 21 | 134 | fits: 90 days to maturity, 134 available after May 14. | — |
| Garlic | — | Sep 18 | 218 | overwinter: Plant Sep 18 to Oct 9; harvest the following summer. | Oct 9 |
| Strawberry | — | Apr 23–Jun 18 | 169 | perennial: A perennial: plant Apr 23; it fruits from the following year and keeps producing for several years. | — |
| Corn | Apr 30 | Jun 4–Jun 11 | 85 | fits: 75 days to maturity, 85 available after Jun 4. | — |
| Pumpkin | May 14 | Jun 11–Jun 11 | 78 | no-fit: Needs 100 days; Idaho Falls has 78 after Jun 11. | — |
| Cauliflower | Apr 16 | May 21–Jun 4 | 127 | fits: 75 days to maturity, 127 available after May 21. | Jun 28 |
| Swiss Chard | Apr 2 | May 14–May 14 | 134 | two-plantings: Plant May 14 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Arugula | — | Apr 2–Jun 25 | 190 | two-plantings: Plant Apr 2 and again by Aug 16; both mature before Oct 9. | Aug 16 |
| Brussel Sprouts | Apr 2 | Apr 30–May 14 | 162 | fits: 100 days to maturity, 162 available after Apr 30. | Jun 17 |
| Butternut Squash | May 14 | Jun 11–Jun 18 | 78 | no-fit: Needs 100 days; Idaho Falls has 78 after Jun 11. | — |
| Eggplant | Apr 9 | Jun 11–Jun 18 | 71 | fits: 70 days to maturity, 71 available after Jun 11. | — |
| Okra | Apr 30 | Jun 4–Jun 11 | 92 | fits: 55 days to maturity, 92 available after Jun 4. | Jun 27 |
| Basil | Apr 23 | Jun 18–Jun 18 | 78 | fits: 60 days to maturity, 78 available after Jun 18. | Jun 22 |
| Cilantro | — | Apr 30–May 21 | 148 | two-plantings: Plant Apr 30 and again by Jul 23; both mature before Sep 25. | Jul 23 |
| Parsley | Mar 19 | Jun 4–Jun 11 | 113 | fits: 70 days to maturity, 113 available after Jun 4. | Jul 3 |
| Celery | Mar 19 | Jun 4–Jun 18 | 113 | head-start: Even planted out Jun 4, the outdoor season is about 7 days short; choose an early variety or grow under cover. | — |
| Scallions | Mar 19 | Apr 30–May 14 | 162 | two-plantings: Plant Apr 30 and again by Jul 27; both mature before Oct 9. | Jul 27 |
| Turnip | — | Apr 30–May 14 | 162 | two-plantings: Plant Apr 30 and again by Aug 6; both mature before Oct 9. | Aug 6 |
| Kohlrabi | — | Apr 16–Apr 30 | 176 | two-plantings: Plant Apr 16 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Bok Choy | Apr 30 | May 21–May 28 | 127 | two-plantings: Plant May 21 and again by Jul 28; both mature before Sep 25. | Jul 28 |
| Collards | Mar 19 | Apr 30–May 14 | 162 | two-plantings: Plant Apr 30 and again by Jul 27; both mature before Oct 9. | Jul 27 |
| Cantaloupe | May 14 | Jun 11–Jun 18 | 71 | head-start: Even planted out Jun 11, the outdoor season is about 14 days short; choose an early variety or grow under cover. | — |
| Chives | Mar 5 | Jun 4–Jun 11 | 127 | fits: 90 days to maturity, 127 available after Jun 4. | — |
| Dill | — | Apr 2–Jun 25 | 176 | two-plantings: Plant Apr 2 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Oregano | Mar 19 | Jun 4–Jun 11 | 127 | fits: 80 days to maturity, 127 available after Jun 4. | — |
| Rosemary | Mar 5 | Jun 4–Jun 11 | 113 | fits: 80 days to maturity, 113 available after Jun 4. | — |
| Sage | Apr 2 | Jun 4–Jun 11 | 127 | fits: 75 days to maturity, 127 available after Jun 4. | — |
| Thyme | Mar 19 | Jun 4–Jun 11 | 127 | fits: 90 days to maturity, 127 available after Jun 4. | — |
| Calendula | Apr 16 | May 14–May 28 | 134 | two-plantings: Plant May 14 and again by Jul 23; both mature before Sep 25. | Jul 23 |
| Cosmos | Apr 30 | May 28–Jun 11 | 99 | fits: 60 days to maturity, 99 available after May 28. | Jun 22 |
| Lavender | Mar 5 | May 28–Jun 11 | 134 | fits: 90 days to maturity, 134 available after May 28. | — |
| Marigolds | Apr 16 | May 28–Jun 4 | 99 | fits: 50 days to maturity, 99 available after May 28. | Jul 2 |
| Melons | May 14 | Jun 11–Jun 18 | 71 | head-start: Even planted out Jun 11, the outdoor season is about 14 days short; choose an early variety or grow under cover. | — |
| Mint | — | May 28–Jun 11 | 134 | fits: 90 days to maturity, 134 available after May 28. | — |
| Nasturtiums | Apr 30 | May 28–Jun 4 | 99 | fits: 55 days to maturity, 99 available after May 28. | Jun 27 |
| Pole Beans | — | Jun 4–Jun 18 | 92 | fits: 65 days to maturity, 92 available after Jun 4. | Jun 17 |
| Spaghetti Squash | May 14 | Jun 11–Jun 18 | 78 | head-start: Even planted out Jun 11, the outdoor season is about 12 days short; choose an early variety or grow under cover. | — |
| Sunflowers | — | May 28–Jun 11 | 99 | fits: 70 days to maturity, 99 available after May 28. | Jun 12 |
| Tomatillos | Apr 2 | Jun 4–Jun 11 | 78 | fits: 75 days to maturity, 78 available after Jun 4. | — |
| Watermelon | May 14 | Jun 4–Jun 11 | 78 | head-start: Even planted out Jun 4, the outdoor season is about 2 days short; choose an early variety or grow under cover. | — |
| Yellow Squash | May 14 | Jun 11–Jun 18 | 85 | fits: 55 days to maturity, 85 available after Jun 11. | Jun 27 |
| Zinnias | Apr 30 | May 28–Jun 11 | 99 | fits: 60 days to maturity, 99 available after May 28. | Jun 22 |
Month by month in Idaho Falls
| 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 5), Lavender (Mar 5), Onion (Mar 5), Rosemary (Mar 5), Celery (Mar 19), Collards (Mar 19), +5 more. |
| April | Start indoors: Broccoli (Apr 2), Brussel Sprouts (Apr 2), Cabbage (Apr 2), Lettuce (Apr 2), Sage (Apr 2), Swiss Chard (Apr 2), +14 more. Direct sow from: Arugula (Apr 2), Beets (Apr 2), Dill (Apr 2), Peas (Apr 2), Radish (Apr 2), Spinach (Apr 2), +3 more. Transplant from: Broccoli (Apr 30), Brussel Sprouts (Apr 30), Cabbage (Apr 30), Collards (Apr 30), Kale (Apr 30), Lettuce (Apr 30), +2 more. Plant: Strawberry (Apr 23). |
| May | Start indoors: Cucumber (May 7), Butternut Squash (May 14), Cantaloupe (May 14), Melons (May 14), Pumpkin (May 14), Spaghetti Squash (May 14), +3 more. Direct sow from: Carrots (May 7), Potatoes (May 14), Sunflowers (May 28). Transplant from: Calendula (May 14), Swiss Chard (May 14), Bok Choy (May 21), Cauliflower (May 21), Cosmos (May 28), Lavender (May 28), +4 more. Last frost around May 28. |
| June | Direct sow from: Beans (Jun 4), Pole Beans (Jun 4). Transplant from: Celery (Jun 4), Chives (Jun 4), Corn (Jun 4), Okra (Jun 4), Oregano (Jun 4), Parsley (Jun 4), +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 Idaho Falls, ID (ZIP 83404)?
The median last spring frost date for Idaho Falls, ID (ZIP code 83404) is around May 28. 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 10; one in ten it runs past June 16.
What is the first fall frost date in Idaho Falls, ID?
The median first fall frost date for Idaho Falls, ID 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 2 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Idaho Falls, ID?
The frost-free growing season in Idaho Falls is about 113 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 Idaho Falls (113 frost-free days, a short season), 31 of 56 planner crops fit outright, 15 get two plantings, 7 need an indoor start, 2 don't reliably mature, 1 crop is perennial.
What USDA hardiness zone is Idaho Falls, ID?
Idaho Falls, ID 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 Idaho Falls, ID?
Start tomatoes indoors Apr 23 and plant out Jun 11 in Idaho Falls. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Idaho Falls?
Two: plant Apr 30 and again by Jul 28; both mature before Sep 25.
When do I plant garlic in Idaho Falls?
Sep 18 to Oct 9; it overwinters and is ready the following summer.
Can I grow Celery in Idaho Falls?
Yes, with help. Even planted out Jun 4, the outdoor season is about 7 days short; choose an early variety or grow under cover.
Nearby and related
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- Frost dates for Rigby, ID 83442 (16.8 mi)
- Frost dates for Blackfoot, ID 83221 (27.2 mi)
- Frost dates for Rexburg, ID 83440 (28.4 mi)
- When to plant in Idaho Falls, ID: month-by-month guide
- When to plant in ID
- When to plant Beans in ID
- When to plant Strawberries in ID
- When to plant Beets in ID
- When to plant Broccoli in ID
- When to plant Carrots in ID
- When to plant Kale in ID
- Look up another ZIP