Frost Dates for Pasco, WA
In Pasco, WA, the average last spring frost is around Apr 27 and the average first fall frost around Oct 11, for a growing season of about 168 days. For frost-tender plants, wait until May 10, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Pasco Tri Cities Airport, WA weather station, under 1 mile away, elevation 407 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% | May 10 | Sep 28 |
| 20% | May 6 | Oct 1 |
| 30% | May 2 | Oct 4 |
| 40% | Apr 29 | Oct 7 |
| 50% | Apr 27 | Oct 11 |
| 60% | Apr 23 | Oct 14 |
| 70% | Apr 19 | Oct 17 |
| 80% | Apr 14 | Oct 21 |
| 90% | Apr 8 | Oct 27 |
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) | May 9 | Sep 29 |
| Frost / freeze (32°F) | Apr 27 | Oct 11 |
| Hard freeze (28°F) | Apr 7 | Oct 23 |
Planting calendar for Pasco
Transplant May 4 – May 18
Transplant May 11 – May 25
Transplant May 11 – May 25
Transplant May 4 – May 18
Sow or transplant May 4 – May 18
Sow or transplant May 4 – May 18
Sow or transplant May 11 – May 25
Sow or transplant Mar 30 – Apr 13
Fall sowing Aug 16 – Sep 13
Fall sowing Aug 16 – Sep 6
Fall sowing Aug 2 – Aug 16
Sow or transplant Mar 30 – Apr 13
Fall sowing Aug 2 – Aug 30
Transplant Apr 13 – Apr 27
Fall sowing Jul 19 – Aug 2
Transplant Apr 6 – Apr 20
Fall sowing Jul 19 – Aug 2
Fall sowing Jul 19 – Aug 2
Fall sowing Aug 30 – Sep 20
Fall sowing Aug 2 – Aug 16
Plant Mar 30 – Apr 13
Based on the average last frost (Apr 27) and first frost (Oct 11). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.