Frost Dates for Klamath Falls, OR 97603
Last spring frost June 11 · First fall frost September 18 · 99 frost-free days · USDA Zone 6b
ZIP 97603 has about 33,200 people, the largest of 2 ZIP codes in Klamath Falls.
Short season: 99 frost-free days. Spring frost risk spans May 24–June 29 (36 days). Fall frost risk spans August 25–October 6 (42 days).
Frost probability for 97603
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | June 29 | June 11 | May 24 |
| Fall (first frost) | August 25 | September 18 | October 6 |
Dates come from NOAA 1971–2000 freeze probabilities at KLAMATH FALLS AG STN (7.0 km away); the 50% date is the median year.
Frost dates by ZIP code in Klamath Falls, OR
| ZIP | Last spring frost (50%) | First fall frost (50%) | Zone |
|---|---|---|---|
| 97603 | June 11 | September 18 | 6b |
| 97601 | June 11 | September 18 | 7a |
Which crops fit a 99-day season in Klamath Falls
In Klamath Falls (99 frost-free days, a short season), 29 of 56 planner crops fit outright, 14 get two plantings, 6 need an indoor start, 6 don't reliably mature, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | May 7 | Jun 25–Jul 2 | 57 | no-fit: Needs 80 days; Klamath Falls has 57 after Jun 25. | — |
| Pepper | Apr 30 | Jun 25–Jul 2 | 57 | head-start: Even planted out Jun 25, the outdoor season is about 18 days short; choose an early variety or grow under cover. | — |
| Lettuce | Apr 16 | May 14–May 21 | 134 | two-plantings: Plant May 14 and again by Jul 28; both mature before Sep 25. | Jul 28 |
| Carrots | — | May 21–May 28 | 141 | fits: 70 days to maturity, 141 available after May 21. | Jul 17 |
| Cucumber | May 21 | Jun 25–Jul 2 | 71 | fits: 60 days to maturity, 71 available after Jun 25. | — |
| Beans | — | Jun 18–Jul 2 | 85 | fits: 60 days to maturity, 85 available after Jun 18. | Jun 29 |
| Peas | — | Apr 16–Jun 25 | 162 | fits: 65 days to maturity, 162 available after Apr 16. | Jul 8 |
| Zucchini | May 28 | Jun 25–Jul 2 | 71 | fits: 55 days to maturity, 71 available after Jun 25. | Jun 27 |
| Onion | Mar 19 | May 14–May 28 | 134 | fits: 100 days to maturity, 134 available after May 14. | — |
| Spinach | — | Apr 16–Jun 4 | 176 | two-plantings: Plant Apr 16 and again by Aug 16; both mature before Oct 9. | Aug 16 |
| Kale | Apr 2 | May 14–May 28 | 148 | two-plantings: Plant May 14 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Broccoli | Apr 16 | May 14–May 28 | 134 | fits: 80 days to maturity, 134 available after May 14. | Jun 23 |
| Cabbage | Apr 16 | May 14–May 28 | 148 | fits: 70 days to maturity, 148 available after May 14. | Jul 17 |
| Radish | — | Apr 16–Jul 9 | 162 | two-plantings: Plant Apr 16 and again by Aug 17; both mature before Sep 25. | Aug 17 |
| Beets | — | Apr 16–Jul 9 | 162 | two-plantings: Plant Apr 16 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Potatoes | — | May 28–Jun 4 | 120 | fits: 90 days to maturity, 120 available after May 28. | — |
| Garlic | — | Sep 18 | 204 | overwinter: Plant Sep 18 to Oct 9; harvest the following summer. | Oct 9 |
| Strawberry | — | May 7–Jul 2 | 155 | perennial: A perennial: plant May 7; it fruits from the following year and keeps producing for several years. | — |
| Corn | May 14 | Jun 18–Jun 25 | 71 | head-start: Even planted out Jun 18, the outdoor season is about 4 days short; choose an early variety or grow under cover. | — |
| Pumpkin | May 28 | Jun 25–Jun 25 | 64 | no-fit: Needs 100 days; Klamath Falls has 64 after Jun 25. | — |
| Cauliflower | Apr 30 | Jun 4–Jun 18 | 113 | fits: 75 days to maturity, 113 available after Jun 4. | Jun 28 |
| Swiss Chard | Apr 16 | May 28–May 28 | 120 | fits: 55 days to maturity, 120 available after May 28. | Jul 18 |
| Arugula | — | Apr 16–Jul 9 | 176 | two-plantings: Plant Apr 16 and again by Aug 16; both mature before Oct 9. | Aug 16 |
| Brussel Sprouts | Apr 16 | May 14–May 28 | 148 | fits: 100 days to maturity, 148 available after May 14. | Jun 17 |
| Butternut Squash | May 28 | Jun 25–Jul 2 | 64 | no-fit: Needs 100 days; Klamath Falls has 64 after Jun 25. | — |
| Eggplant | Apr 23 | Jun 25–Jul 2 | 57 | head-start: Even planted out Jun 25, the outdoor season is about 13 days short; choose an early variety or grow under cover. | — |
| Okra | May 14 | Jun 18–Jun 25 | 78 | fits: 55 days to maturity, 78 available after Jun 18. | Jun 27 |
| Basil | May 7 | Jul 2–Jul 2 | 64 | fits: 60 days to maturity, 64 available after Jul 2. | — |
| Cilantro | — | May 14–Jun 4 | 134 | two-plantings: Plant May 14 and again by Jul 23; both mature before Sep 25. | Jul 23 |
| Parsley | Apr 2 | Jun 18–Jun 25 | 99 | fits: 70 days to maturity, 99 available after Jun 18. | Jul 3 |
| Celery | Apr 2 | Jun 18–Jul 2 | 99 | head-start: Even planted out Jun 18, the outdoor season is about 21 days short; choose an early variety or grow under cover. | — |
| Scallions | Apr 2 | May 14–May 28 | 148 | two-plantings: Plant May 14 and again by Jul 27; both mature before Oct 9. | Jul 27 |
| Turnip | — | May 14–May 28 | 148 | two-plantings: Plant May 14 and again by Aug 6; both mature before Oct 9. | Aug 6 |
| Kohlrabi | — | Apr 30–May 14 | 162 | two-plantings: Plant Apr 30 and again by Aug 1; both mature before Oct 9. | Aug 1 |
| Bok Choy | May 14 | Jun 4–Jun 11 | 113 | two-plantings: Plant Jun 4 and again by Jul 28; both mature before Sep 25. | Jul 28 |
| Collards | Apr 2 | May 14–May 28 | 148 | two-plantings: Plant May 14 and again by Jul 27; both mature before Oct 9. | Jul 27 |
| Cantaloupe | May 28 | Jun 25–Jul 2 | 57 | no-fit: Needs 85 days; Klamath Falls has 57 after Jun 25. | — |
| Chives | Mar 19 | Jun 18–Jun 25 | 113 | fits: 90 days to maturity, 113 available after Jun 18. | — |
| Dill | — | Apr 16–Jul 9 | 162 | two-plantings: Plant Apr 16 and again by Jul 18; both mature before Sep 25. | Jul 18 |
| Oregano | Apr 2 | Jun 18–Jun 25 | 113 | fits: 80 days to maturity, 113 available after Jun 18. | — |
| Rosemary | Mar 19 | Jun 18–Jun 25 | 99 | fits: 80 days to maturity, 99 available after Jun 18. | — |
| Sage | Apr 16 | Jun 18–Jun 25 | 113 | fits: 75 days to maturity, 113 available after Jun 18. | — |
| Thyme | Apr 2 | Jun 18–Jun 25 | 113 | fits: 90 days to maturity, 113 available after Jun 18. | — |
| Calendula | Apr 30 | May 28–Jun 11 | 120 | two-plantings: Plant May 28 and again by Jul 23; both mature before Sep 25. | Jul 23 |
| Cosmos | May 14 | Jun 11–Jun 25 | 85 | fits: 60 days to maturity, 85 available after Jun 11. | Jun 22 |
| Lavender | Mar 19 | Jun 11–Jun 25 | 120 | fits: 90 days to maturity, 120 available after Jun 11. | — |
| Marigolds | Apr 30 | Jun 11–Jun 18 | 85 | fits: 50 days to maturity, 85 available after Jun 11. | Jul 2 |
| Melons | May 28 | Jun 25–Jul 2 | 57 | no-fit: Needs 85 days; Klamath Falls has 57 after Jun 25. | — |
| Mint | — | Jun 11–Jun 25 | 120 | fits: 90 days to maturity, 120 available after Jun 11. | — |
| Nasturtiums | May 14 | Jun 11–Jun 18 | 85 | fits: 55 days to maturity, 85 available after Jun 11. | Jun 27 |
| Pole Beans | — | Jun 18–Jul 2 | 78 | fits: 65 days to maturity, 78 available after Jun 18. | — |
| Spaghetti Squash | May 28 | Jun 25–Jul 2 | 64 | no-fit: Needs 90 days; Klamath Falls has 64 after Jun 25. | — |
| Sunflowers | — | Jun 11–Jun 25 | 85 | fits: 70 days to maturity, 85 available after Jun 11. | Jun 12 |
| Tomatillos | Apr 16 | Jun 18–Jun 25 | 64 | head-start: Even planted out Jun 18, the outdoor season is about 11 days short; choose an early variety or grow under cover. | — |
| Watermelon | May 28 | Jun 18–Jun 25 | 64 | head-start: Even planted out Jun 18, the outdoor season is about 16 days short; choose an early variety or grow under cover. | — |
| Yellow Squash | May 28 | Jun 25–Jul 2 | 71 | fits: 55 days to maturity, 71 available after Jun 25. | Jun 27 |
| Zinnias | May 14 | Jun 11–Jun 25 | 85 | fits: 60 days to maturity, 85 available after Jun 11. | Jun 22 |
Month by month in Klamath 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 19), Lavender (Mar 19), Onion (Mar 19), Rosemary (Mar 19). |
| April | Start indoors: Celery (Apr 2), Collards (Apr 2), Kale (Apr 2), Oregano (Apr 2), Parsley (Apr 2), Scallions (Apr 2), +13 more. Direct sow from: Arugula (Apr 16), Beets (Apr 16), Dill (Apr 16), Peas (Apr 16), Radish (Apr 16), Spinach (Apr 16), +1 more. |
| May | Start indoors: Basil (May 7), Tomato (May 7), Bok Choy (May 14), Corn (May 14), Cosmos (May 14), Nasturtiums (May 14), +11 more. Direct sow from: Cilantro (May 14), Turnip (May 14), Carrots (May 21), Potatoes (May 28). Transplant from: Broccoli (May 14), Brussel Sprouts (May 14), Cabbage (May 14), Collards (May 14), Kale (May 14), Lettuce (May 14), +4 more. Plant: Strawberry (May 7). |
| June | Direct sow from: Sunflowers (Jun 11), Beans (Jun 18), Pole Beans (Jun 18). Transplant from: Bok Choy (Jun 4), Cauliflower (Jun 4), Cosmos (Jun 11), Lavender (Jun 11), Marigolds (Jun 11), Mint (Jun 11), +24 more. Last frost around June 11. Last sowing dates: Sunflowers (Jun 12), Brussel Sprouts (Jun 17), Cosmos (Jun 22), Zinnias (Jun 22), Broccoli (Jun 23), Nasturtiums (Jun 27), +5 more. |
| July | Transplant from: Basil (Jul 2). 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 Klamath Falls, OR (ZIP 97603)?
The median last spring frost date for Klamath Falls, OR (ZIP code 97603) is around June 11. 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 24; one in ten it runs past June 29.
What is the first fall frost date in Klamath Falls, OR?
The median first fall frost date for Klamath Falls, OR 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 August 25 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Klamath Falls, OR?
The frost-free growing season in Klamath Falls is about 99 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 Klamath Falls (99 frost-free days, a short season), 29 of 56 planner crops fit outright, 14 get two plantings, 6 need an indoor start, 6 don't reliably mature, 1 crop is perennial.
What USDA hardiness zone is Klamath Falls, OR?
Klamath Falls, OR is in USDA hardiness zone 6b (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 Klamath Falls, OR?
Start tomatoes indoors May 7 and plant out Jun 25 in Klamath 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 Klamath Falls?
Two: plant May 14 and again by Jul 28; both mature before Sep 25.
When do I plant garlic in Klamath Falls?
Sep 18 to Oct 9; it overwinters and is ready the following summer.
Can I grow Celery in Klamath Falls?
Yes, with help. Even planted out Jun 18, the outdoor season is about 21 days short; choose an early variety or grow under cover.
Which nearby ZIP has a longer season?
Ashland (ZIP 97520) has 144 frost-free days, 45 more than Klamath Falls (ZIP 97603). See Ashland ZIP 97520 frost dates
Nearby and related
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- When to plant in OR
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