Frost Dates for Gresham, OR
In Gresham, OR, the average last spring frost is around Mar 16 and the average first fall frost around Nov 20, for a growing season of about 250 days. For frost-tender plants, wait until Apr 12, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Portland Troutdale Airport, OR weather station, 4 miles away, elevation 29 ft. Frost can come earlier in low spots and valleys and later near cities and large lakes.
Frost probability by date
Chance of a 32°F frost after the spring date, or before the fall date.
| Chance | Last spring frost | First fall frost |
|---|---|---|
| 10% | Apr 12 | Oct 30 |
| 20% | Apr 2 | Nov 4 |
| 30% | Mar 27 | Nov 9 |
| 40% | Mar 21 | Nov 15 |
| 50% | Mar 16 | Nov 20 |
| 60% | Mar 10 | Nov 26 |
| 70% | Mar 3 | Dec 1 |
| 80% | Feb 26 | Dec 7 |
| 90% | Feb 18 | Dec 17 |
Light frost vs. hard freeze
Average (50%) dates for each temperature. Tender plants are damaged at 36°F; most hardy crops survive until 28°F.
| Temperature | Last in spring | First in fall |
|---|---|---|
| Light frost (36°F) | Apr 19 | Oct 30 |
| Frost / freeze (32°F) | Mar 16 | Nov 20 |
| Hard freeze (28°F) | Feb 14 | Dec 15 |
Planting calendar for Gresham
Transplant Mar 23 – Apr 6
Transplant Mar 30 – Apr 13
Transplant Mar 30 – Apr 13
Transplant Mar 23 – Apr 6
Sow or transplant Mar 23 – Apr 6
Sow or transplant Mar 23 – Apr 6
Sow or transplant Mar 30 – Apr 13
Sow or transplant Feb 16 – Mar 2
Fall sowing Sep 25 – Oct 23
Fall sowing Sep 25 – Oct 16
Fall sowing Sep 11 – Sep 25
Sow or transplant Feb 16 – Mar 2
Fall sowing Sep 11 – Oct 9
Transplant Mar 2 – Mar 16
Fall sowing Aug 28 – Sep 11
Transplant Feb 23 – Mar 9
Fall sowing Aug 28 – Sep 11
Fall sowing Aug 28 – Sep 11
Fall sowing Oct 9 – Oct 30
Fall sowing Sep 11 – Sep 25
Plant Feb 16 – Mar 2
Based on the average last frost (Mar 16) and first frost (Nov 20). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.