USDA zone 7a in Oregon
USDA plant hardiness zone 7a covers 23 locations across Oregon (average annual extreme minimum 0 to 5 °F): Camp Sherman, OR, Cayuse, OR, Condon, OR, Dayville, OR, Enterprise, OR, Fossil, OR, and 17 more. Average last spring frost across this group ranges March 25 (Milton-Freewater) to June 8 (Rocky Point), and growing seasons run 84–218 days (Enterprise to Milton-Freewater) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Oregon location's own frost dates; the printable planting calendar uses Vale, this group's median-season location.
- USDA zone
- 7a0 to 5 °F
- Last frost range
- Mar 25–Jun 8avg, 32°F
- First frost range
- Sep 5–Oct 29avg, 32°F
- Growing season range
- 84–218days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Camp Sherman | — | Marion Forks Fish Hatchery | May 15 | Sep 30 | 134 |
| Cayuse | Helix | Pendleton Branch Exp Stn | May 12 | Sep 27 | 135 |
| Condon | — | Condon | May 10 | Oct 7 | 148 |
| Dayville | Monument, Spray | John Day 35 Wnw | Apr 30 | Oct 14 | 167 |
| Enterprise | — | Enterprise 20 Nne | Jun 8 | Sep 5 | 84 |
| Fossil | — | Fossil | Jun 3 | Sep 14 | 98 |
| Grass Valley | — | Kent | May 15 | Oct 11 | 147 |
| Grass Valley | Moro | Moro | May 12 | Oct 4 | 143 |
| Halfway | — | Halfway | May 15 | Sep 24 | 130 |
| Heppner | Lexington | Heppner | Apr 26 | Oct 19 | 174 |
| Huntington | — | Huntington | Apr 23 | Oct 13 | 172 |
| Jordan Valley | Marsing, Melba | Reynolds | May 21 | Sep 28 | 126 |
| Madras | — | Madras 2 N | May 19 | Oct 4 | 136 |
| Milton-Freewater | Athena, Weston | Milton Freewater | Mar 25 | Oct 29 | 218 |
| Monument | — | Monument 2 | May 9 | Sep 27 | 139 |
| Ontario | Fruitland | Ontario Muni Ap | Apr 21 | Oct 14 | 176 |
| Pendleton | — | Pendleton Dwtn | Apr 22 | Oct 9 | 170 |
| Rhododendron | Wamic | Government Camp | May 27 | Oct 9 | 134 |
| Rocky Point | — | Howard Prairie Dam | Jun 8 | Sep 24 | 108 |
| Shaniko | Antelope | Antelope 6 Ssw | May 22 | Oct 3 | 131 |
| Stanfield | Echo | Hermiston Muni Ap | Apr 26 | Oct 10 | 167 |
| Vale * | — | Vale | May 8 | Sep 29 | 140 |
| Warm Springs | Maupin, Culver | Pelton Dam | May 5 | Oct 7 | 154 |
* Vale is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Vale, representative)
Computed from Vale's average frost dates — the median-season location in this Oregonzone 7a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Mar 13 – Mar 27 | May 15 – May 22 | Jul 14 – Aug 3 | — | matures comfortably |
| Pepper | Very tender | Feb 27 – Mar 13 | May 22 – May 29 | Jul 21 – Aug 20 | — | matures comfortably |
| Cucumber | Tender | Apr 10 – Apr 17 | May 15 – May 22 | Jul 4 – Jul 24 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | May 15 – May 22 | Jun 29 – Jul 14 | — | matures comfortably |
| Bush bean | Tender | — | May 15 – May 22 | Jul 4 – Jul 14 | Jul 31 – Aug 10 | matures comfortably |
| Sweet corn | Tender | — | May 8 – May 22 | Jul 7 – Aug 6 | — | matures comfortably |
| Basil | Very tender | Mar 27 – Apr 10 | May 15 – May 22 | Jun 14 – Jun 29 | — | matures comfortably |
| Lettuce | Half-hardy | Mar 27 – Apr 10 | Apr 10 – Apr 24 | May 25 – Jun 9 | Jul 17 – Aug 1 | matures comfortably |
| Pea | Hardy | — | Mar 27 – Apr 10 | May 21 – Jun 5 | Jul 7 – Jul 22 | matures comfortably |
| Spinach | Hardy | — | Mar 27 – Apr 10 | May 6 – May 16 | Jul 27 – Aug 6 | matures comfortably |
| Carrot | Half-hardy | — | Apr 17 – Apr 24 | Jun 16 – Jul 6 | Jun 27 – Jul 17 | matures comfortably |
| Broccoli | Half-hardy | Mar 13 – Mar 27 | Apr 10 – Apr 24 | Jun 4 – Jun 24 | Jul 2 – Jul 22 | matures comfortably |
Which crops fit this growing season
Using Vale's own 140-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Vale)
From NOAA's 1991–2020 Climate Normals at station USC00358797. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | May 31 | Jun 21 | Sep 17 | Oct 1 | 108 |
| 32°F (freeze) | May 8 | Jun 7 | Sep 29 | Oct 11 | 140 |
| 28°F | Apr 25 | May 14 | Oct 9 | Oct 22 | 167 |
| 24°F | Apr 9 | Apr 27 | Oct 22 | Nov 4 | 194 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 23 locations is 2,282; Vale's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 2,730 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 4,823 | cool-season crops (brassicas, greens) |
Hardiness zone 7a in Oregon
Zone 7a means an average annual extreme minimum winter temperature of about 0 to 5 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Oregon spans 9 hardiness zones in this dataset — see all Oregon locations for the full range, including zones5b, 6a, 6b, 7b, 8a, 8b, 9a, 9b.
Explore zone 7a in other states at zone 7a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 7a mean in Oregon?
- Zone 7a means an average annual extreme minimum winter temperature of 0 to 5 °F — the standard USDA measure of which perennials survive winter. 23 locations in Oregon fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Oregon's zone 7a is the growing season longest?
- Milton-Freewater runs the longest season on this page at about 218 days; Enterprise is shortest at about 84 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Oregon's zone 7a?
- Using Vale's frost dates (this page's median-season location): start seeds indoors about Mar 13 – Mar 27, then transplant outside about May 15 – May 22. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Oregon's zone 7a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 23 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.