Frost dates for 97203 — Portland, OR
How Portland compares
- In 8 years out of 10, the last spring frost in Portland falls between March 6 and April 18, a 43-day window. The first fall frost falls between October 22 and November 30.
- The median last frost is 18 days earlier than the Oregon median of Apr 16.
- Its 225-day growing season is longer than 75% of the 345 Oregon places with a regular frost season (state median 193 days).
- The last frost is 26 days later than the zone 9a median of Mar 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 9a chart.
- The weather station records an average of 45 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 6 |
| 50% (median) | March 29 |
| 10% (safe for tender plants) | April 18 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 22 |
| 50% (median) | November 9 |
| 90% (late) | November 30 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Portland, OR
Frost dates for 97203 — Portland, OR — last frost Mar 29, first frost Nov 9, zone 9a. whenisthelastfrost.com
When to plant vegetables in Portland, OR
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 4 – Jan 18 | Mar 1 – Mar 15 | — | — |
| Peppers | Jan 18 – Feb 1 | Apr 12 – Apr 26 | — | — |
| Eggplant | Jan 18 – Feb 1 | Apr 12 – Apr 26 | — | — |
| Tomatoes | Feb 1 – Feb 15 | Apr 5 – Apr 19 | — | — |
| Lettuce | Feb 1 – Feb 15 | Mar 8 – Mar 22 | Mar 1 – Apr 5 | Sep 14 – Oct 12 |
| Kale | Feb 1 – Feb 15 | Mar 1 – Mar 15 | Mar 1 – Mar 15 | Aug 31 – Sep 21 |
| Broccoli | Feb 1 – Feb 15 | Mar 15 – Mar 29 | — | Aug 3 – Aug 24 |
| Cabbage | Feb 1 – Feb 15 | Mar 8 – Mar 22 | — | Aug 3 – Aug 24 |
| Cauliflower | Feb 1 – Feb 15 | Mar 15 – Mar 29 | — | Aug 3 – Aug 24 |
| Okra | Feb 15 – Mar 1 | Apr 19 – May 3 | Apr 19 – May 3 | — |
| Basil | Feb 15 – Mar 1 | Apr 5 – Apr 19 | — | — |
| Peas | — | — | Feb 15 – Mar 8 | Aug 17 – Sep 7 |
| Spinach | — | — | Feb 15 – Mar 8 | Sep 14 – Oct 5 |
| Radishes | — | — | Feb 22 – Apr 5 | Sep 28 – Oct 19 |
| Cucumbers | Mar 1 – Mar 8 | Apr 12 – Apr 19 | Apr 5 – Apr 19 | Aug 24 – Sep 7 |
| Zucchini & Summer Squash | Mar 1 – Mar 8 | — | Apr 5 – Apr 19 | Aug 31 – Sep 14 |
| Winter Squash & Pumpkins | Mar 1 – Mar 8 | — | Apr 5 – Apr 19 | — |
| Melons & Watermelon | Mar 1 – Mar 8 | Apr 12 – Apr 26 | — | — |
| Carrots | — | — | Mar 8 – Apr 5 | Aug 17 – Aug 31 |
| Beets | — | — | Mar 8 – Apr 5 | Aug 31 – Sep 14 |
| Potatoes | — | — | Mar 8 – Mar 29 | — |
| Swiss Chard | — | — | Mar 15 – Apr 12 | Aug 31 – Sep 14 |
| Cilantro | — | — | Mar 15 – Apr 5 | Sep 14 – Oct 5 |
| Green Beans | — | — | Apr 5 – Apr 26 | Aug 24 – Sep 7 |
| Sweet Corn | — | — | Apr 5 – Apr 19 | — |
| Sweet Potatoes | — | Apr 12 – May 3 | — | — |
| Garlic | — | — | — | Oct 26 – Nov 30 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Vancouver Pearson Ap, WA weather station, 7 km away (elevation 30 ft (9 m)).
ZIP codes in Portland: 97201 97202 97203 97204 97205 97206 97207 97208 97209 97210 97211 97212 97213 97214 97215 97216 97217 97218 97219 97220 97221 97222 97223 97224 97225 97227 97228 97229 97230 97231 97232 97233 97236 97238 97239 97240 97242 97250 97251 97252 97253 97254 97256 97258 97266 97267 97268 97269 97280 97281 97282 97283 97286 97290 97291 97292 97293 97294 97296 97298
Frost dates near Portland
- Beaverton Feb 11 · Dec 5
- Hillsboro Apr 16 · Oct 23
- Lake Oswego Mar 18 · Nov 18
- Marylhurst Mar 18 · Nov 18
- Happy Valley Mar 18 · Nov 18
- Scappoose Apr 10 · Nov 2
- Fairview Mar 16 · Nov 20
- Tualatin Apr 1 · Nov 6
Frequently asked questions
When is the last frost in Portland, OR?
The median last spring frost in Portland, OR is March 29. There is still about a 10% chance of frost after April 18, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Portland, OR?
The median first fall frost is November 9, with about a 10% chance of frost before October 22.
How long is the growing season in Portland, OR?
About 225 days between the median last spring frost and first fall frost.
What planting zone is Portland, OR?
Portland, OR is in USDA hardiness zone 9a.