Frost Dates for Hillsboro, OR 97124
Last spring frost April 20 · First fall frost October 24 · 187 frost-free days · USDA Zone 8b
ZIP 97124 has about 54,400 people, the largest of 2 ZIP codes in Hillsboro.
Long season: 187 frost-free days. Spring frost risk spans March 30–May 10 (41 days). Fall frost risk spans October 5–November 10 (36 days).
Frost probability for 97124
| Frost | 10% | 50% | 90% |
|---|---|---|---|
| Spring (last frost) | May 10 | April 20 | March 30 |
| Fall (first frost) | October 5 | October 24 | November 10 |
Dates come from NOAA 1971–2000 freeze probabilities at VANCOUVER 4 NNE (25.8 km away); the 50% date is the median year.
Frost dates by ZIP code in Hillsboro, OR
| ZIP | Last spring frost (50%) | First fall frost (50%) | Zone |
|---|---|---|---|
| 97124 | April 20 | October 24 | 8b |
| 97123 | April 15 | October 29 | 8b |
Which crops fit a 187-day season in Hillsboro
In Hillsboro (187 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
| Crop | Start indoors | Plant out / sow | Days you have | Verdict | Last sow date |
|---|---|---|---|---|---|
| Tomato | Mar 16 | May 4–May 11 | 145 | fits: 80 days to maturity, 145 available after May 4. | Jun 24 |
| Pepper | Mar 9 | May 4–May 11 | 145 | fits: 75 days to maturity, 145 available after May 4. | Jun 29 |
| Lettuce | Feb 23 | Mar 23–Mar 30 | 222 | two-plantings: Plant Mar 23 and again by Sep 2; both mature before Oct 31. | Sep 2 |
| Carrots | — | Mar 30–Apr 6 | 229 | fits: 70 days to maturity, 229 available after Mar 30. | Aug 22 |
| Cucumber | Mar 30 | May 4–May 11 | 159 | two-plantings: Plant May 4 and again by Jul 28; both mature before Oct 10. | Jul 28 |
| Beans | — | Apr 27–May 11 | 173 | two-plantings: Plant Apr 27 and again by Aug 4; both mature before Oct 17. | Aug 4 |
| Peas | — | Feb 23–May 4 | 250 | fits: 65 days to maturity, 250 available after Feb 23. | Aug 13 |
| Zucchini | Apr 6 | May 4–May 11 | 159 | two-plantings: Plant May 4 and again by Aug 2; both mature before Oct 10. | Aug 2 |
| Onion | Jan 26 | Mar 23–Apr 6 | 222 | fits: 100 days to maturity, 222 available after Mar 23. | — |
| Spinach | — | Feb 23–Apr 13 | 264 | two-plantings: Plant Feb 23 and again by Sep 21; both mature before Nov 14. | Sep 21 |
| Kale | Feb 9 | Mar 23–Apr 6 | 236 | two-plantings: Plant Mar 23 and again by Sep 6; both mature before Nov 14. | Sep 6 |
| Broccoli | Feb 23 | Mar 23–Apr 6 | 222 | fits: 80 days to maturity, 222 available after Mar 23. | Jul 29 |
| Cabbage | Feb 23 | Mar 23–Apr 6 | 236 | fits: 70 days to maturity, 236 available after Mar 23. | Aug 22 |
| Radish | — | Feb 23–May 18 | 250 | two-plantings: Plant Feb 23 and again by Sep 22; both mature before Oct 31. | Sep 22 |
| Beets | — | Feb 23–May 18 | 250 | two-plantings: Plant Feb 23 and again by Aug 23; both mature before Oct 31. | Aug 23 |
| Potatoes | — | Apr 6–Apr 13 | 208 | fits: 90 days to maturity, 208 available after Apr 6. | — |
| Garlic | — | Oct 24 | 292 | overwinter: Plant Oct 24 to Nov 14; harvest the following summer. | Nov 14 |
| Strawberry | — | Mar 16–May 11 | 243 | perennial: A perennial: plant Mar 16; it fruits from the following year and keeps producing for several years. | — |
| Corn | Mar 23 | Apr 27–May 4 | 159 | fits: 75 days to maturity, 159 available after Apr 27. | Jul 6 |
| Pumpkin | Apr 6 | May 4–May 4 | 152 | fits: 100 days to maturity, 152 available after May 4. | Jun 11 |
| Cauliflower | Mar 9 | Apr 13–Apr 27 | 201 | fits: 75 days to maturity, 201 available after Apr 13. | Aug 3 |
| Swiss Chard | Feb 23 | Apr 6–Apr 6 | 208 | two-plantings: Plant Apr 6 and again by Aug 23; both mature before Oct 31. | Aug 23 |
| Arugula | — | Feb 23–May 18 | 264 | two-plantings: Plant Feb 23 and again by Sep 21; both mature before Nov 14. | Sep 21 |
| Brussel Sprouts | Feb 23 | Mar 23–Apr 6 | 236 | fits: 100 days to maturity, 236 available after Mar 23. | Jul 23 |
| Butternut Squash | Apr 6 | May 4–May 11 | 152 | fits: 100 days to maturity, 152 available after May 4. | Jun 11 |
| Eggplant | Mar 2 | May 4–May 11 | 145 | fits: 70 days to maturity, 145 available after May 4. | Jul 4 |
| Okra | Mar 23 | Apr 27–May 4 | 166 | two-plantings: Plant Apr 27 and again by Aug 2; both mature before Oct 10. | Aug 2 |
| Basil | Mar 16 | May 11–May 11 | 152 | two-plantings: Plant May 11 and again by Jul 28; both mature before Oct 10. | Jul 28 |
| Cilantro | — | Mar 23–Apr 13 | 222 | two-plantings: Plant Mar 23 and again by Aug 28; both mature before Oct 31. | Aug 28 |
| Parsley | Feb 9 | Apr 27–May 4 | 187 | fits: 70 days to maturity, 187 available after Apr 27. | Aug 8 |
| Celery | Feb 9 | Apr 27–May 11 | 187 | fits: 120 days to maturity, 187 available after Apr 27. | Jun 19 |
| Scallions | Feb 9 | Mar 23–Apr 6 | 236 | two-plantings: Plant Mar 23 and again by Sep 1; both mature before Nov 14. | Sep 1 |
| Turnip | — | Mar 23–Apr 6 | 236 | two-plantings: Plant Mar 23 and again by Sep 11; both mature before Nov 14. | Sep 11 |
| Kohlrabi | — | Mar 9–Mar 23 | 250 | two-plantings: Plant Mar 9 and again by Sep 6; both mature before Nov 14. | Sep 6 |
| Bok Choy | Mar 23 | Apr 13–Apr 20 | 201 | two-plantings: Plant Apr 13 and again by Sep 2; both mature before Oct 31. | Sep 2 |
| Collards | Feb 9 | Mar 23–Apr 6 | 236 | two-plantings: Plant Mar 23 and again by Sep 1; both mature before Nov 14. | Sep 1 |
| Cantaloupe | Apr 6 | May 4–May 11 | 145 | fits: 85 days to maturity, 145 available after May 4. | Jun 19 |
| Chives | Jan 26 | Apr 27–May 4 | 201 | fits: 90 days to maturity, 201 available after Apr 27. | — |
| Dill | — | Feb 23–May 18 | 250 | two-plantings: Plant Feb 23 and again by Aug 23; both mature before Oct 31. | Aug 23 |
| Oregano | Feb 9 | Apr 27–May 4 | 201 | fits: 80 days to maturity, 201 available after Apr 27. | — |
| Rosemary | Jan 26 | Apr 27–May 4 | 187 | fits: 80 days to maturity, 187 available after Apr 27. | — |
| Sage | Feb 23 | Apr 27–May 4 | 201 | fits: 75 days to maturity, 201 available after Apr 27. | — |
| Thyme | Feb 9 | Apr 27–May 4 | 201 | fits: 90 days to maturity, 201 available after Apr 27. | — |
| Calendula | Mar 9 | Apr 6–Apr 20 | 208 | two-plantings: Plant Apr 6 and again by Aug 28; both mature before Oct 31. | Aug 28 |
| Cosmos | Mar 23 | Apr 20–May 4 | 173 | two-plantings: Plant Apr 20 and again by Jul 28; both mature before Oct 10. | Jul 28 |
| Lavender | Jan 26 | Apr 20–May 4 | 208 | fits: 90 days to maturity, 208 available after Apr 20. | — |
| Marigolds | Mar 9 | Apr 20–Apr 27 | 173 | two-plantings: Plant Apr 20 and again by Aug 7; both mature before Oct 10. | Aug 7 |
| Melons | Apr 6 | May 4–May 11 | 145 | fits: 85 days to maturity, 145 available after May 4. | Jun 19 |
| Mint | — | Apr 20–May 4 | 208 | fits: 90 days to maturity, 208 available after Apr 20. | — |
| Nasturtiums | Mar 23 | Apr 20–Apr 27 | 173 | two-plantings: Plant Apr 20 and again by Aug 2; both mature before Oct 10. | Aug 2 |
| Pole Beans | — | Apr 27–May 11 | 166 | fits: 65 days to maturity, 166 available after Apr 27. | Jul 23 |
| Spaghetti Squash | Apr 6 | May 4–May 11 | 152 | fits: 90 days to maturity, 152 available after May 4. | Jun 21 |
| Sunflowers | — | Apr 20–May 4 | 173 | fits: 70 days to maturity, 173 available after Apr 20. | Jul 18 |
| Tomatillos | Feb 23 | Apr 27–May 4 | 152 | fits: 75 days to maturity, 152 available after Apr 27. | Jun 29 |
| Watermelon | Apr 6 | Apr 27–May 4 | 152 | fits: 80 days to maturity, 152 available after Apr 27. | Jun 24 |
| Yellow Squash | Apr 6 | May 4–May 11 | 159 | two-plantings: Plant May 4 and again by Aug 2; both mature before Oct 10. | Aug 2 |
| Zinnias | Mar 23 | Apr 20–May 4 | 173 | two-plantings: Plant Apr 20 and again by Jul 28; both mature before Oct 10. | Jul 28 |
Month by month in Hillsboro
| Month | What to do |
|---|---|
| January | Start indoors: Chives (Jan 26), Lavender (Jan 26), Onion (Jan 26), Rosemary (Jan 26). |
| February | Start indoors: Celery (Feb 9), Collards (Feb 9), Kale (Feb 9), Oregano (Feb 9), Parsley (Feb 9), Scallions (Feb 9), +8 more. Direct sow from: Arugula (Feb 23), Beets (Feb 23), Dill (Feb 23), Peas (Feb 23), Radish (Feb 23), Spinach (Feb 23). |
| March | Start indoors: Eggplant (Mar 2), Calendula (Mar 9), Cauliflower (Mar 9), Marigolds (Mar 9), Pepper (Mar 9), Basil (Mar 16), +8 more. Direct sow from: Kohlrabi (Mar 9), Cilantro (Mar 23), Turnip (Mar 23), Carrots (Mar 30). Transplant from: Broccoli (Mar 23), Brussel Sprouts (Mar 23), Cabbage (Mar 23), Collards (Mar 23), Kale (Mar 23), Lettuce (Mar 23), +2 more. Plant: Strawberry (Mar 16). |
| April | Start indoors: Butternut Squash (Apr 6), Cantaloupe (Apr 6), Melons (Apr 6), Pumpkin (Apr 6), Spaghetti Squash (Apr 6), Watermelon (Apr 6), +2 more. Direct sow from: Potatoes (Apr 6), Sunflowers (Apr 20), Beans (Apr 27), Pole Beans (Apr 27). Transplant from: Calendula (Apr 6), Swiss Chard (Apr 6), Bok Choy (Apr 13), Cauliflower (Apr 13), Cosmos (Apr 20), Lavender (Apr 20), +15 more. Last frost around April 20. |
| May | Transplant from: Butternut Squash (May 4), Cantaloupe (May 4), Cucumber (May 4), Eggplant (May 4), Melons (May 4), Pepper (May 4), +6 more. |
| June | Last sowing dates: Butternut Squash (Jun 11), Pumpkin (Jun 11), Cantaloupe (Jun 19), Celery (Jun 19), Melons (Jun 19), Spaghetti Squash (Jun 21), +4 more. |
| July | Last sowing dates: Eggplant (Jul 4), Corn (Jul 6), Sunflowers (Jul 18), Brussel Sprouts (Jul 23), Pole Beans (Jul 23), Basil (Jul 28), +4 more. |
| August | Last sowing dates: Nasturtiums (Aug 2), Okra (Aug 2), Yellow Squash (Aug 2), Zucchini (Aug 2), Cauliflower (Aug 3), Beans (Aug 4), +10 more. |
| September | Last sowing dates: Collards (Sep 1), Scallions (Sep 1), Bok Choy (Sep 2), Lettuce (Sep 2), Kale (Sep 6), Kohlrabi (Sep 6), +4 more. |
| October | Direct sow from: Garlic (Oct 24). First frost around October 24. |
| November | Last sowing dates: Garlic (Nov 14). |
| 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 Hillsboro, OR (ZIP 97124)?
The median last spring frost date for Hillsboro, OR (ZIP code 97124) is around April 20. 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 March 30; one in ten it runs past May 10.
What is the first fall frost date in Hillsboro, OR?
The median first fall frost date for Hillsboro, OR is around October 24. 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 October 5 in the earliest one-in-ten years, so cover tomatoes and peppers from then.
How long is the growing season in Hillsboro, OR?
The frost-free growing season in Hillsboro is about 187 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 Hillsboro (187 frost-free days, a long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.
What USDA hardiness zone is Hillsboro, OR?
Hillsboro, OR is in USDA hardiness zone 8b (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 Hillsboro, OR?
Start tomatoes indoors Mar 16 and plant out May 4 in Hillsboro. The planner uses the local median last frost and this crop's indoor-start and transplant offsets.
How many plantings of lettuce fit in Hillsboro?
Two: plant Mar 23 and again by Sep 2; both mature before Oct 31.
When do I plant garlic in Hillsboro?
Oct 24 to Nov 14; it overwinters and is ready the following summer.
Can I get two tomato crops in Hillsboro?
Yes: plant out May 4 for a summer crop, and set out a second round of transplants by Jun 24 for a fall crop.
Which nearby ZIP has a longer season?
Portland (ZIP 97229) has 203 frost-free days, 16 more than Hillsboro (ZIP 97124). See Portland ZIP 97229 frost dates
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