Frost Dates for Moscow, ID
In Moscow, ID, the average last spring frost is around Apr 29 and the average first fall frost around Oct 2, for a growing season of about 159 days. For frost-tender plants, wait until May 14, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Pullman Moscow Rgnl Airport, WA weather station, 5 miles away, elevation 2,551 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 14 | Sep 17 |
| 20% | May 8 | Sep 23 |
| 30% | May 5 | Sep 27 |
| 40% | May 1 | Sep 30 |
| 50% | Apr 29 | Oct 2 |
| 60% | Apr 25 | Oct 6 |
| 70% | Apr 21 | Oct 10 |
| 80% | Apr 15 | Oct 16 |
| 90% | Apr 7 | Oct 25 |
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 18 | Sep 19 |
| Frost / freeze (32°F) | Apr 29 | Oct 2 |
| Hard freeze (28°F) | Apr 3 | Oct 18 |
Planting calendar for Moscow
Transplant May 6 – May 20
Transplant May 13 – May 27
Transplant May 13 – May 27
Transplant May 6 – May 20
Sow or transplant May 6 – May 20
Sow or transplant May 6 – May 20
Sow or transplant May 13 – May 27
Sow or transplant Apr 1 – Apr 15
Fall sowing Aug 7 – Sep 4
Fall sowing Aug 7 – Aug 28
Fall sowing Jul 24 – Aug 7
Sow or transplant Apr 1 – Apr 15
Fall sowing Jul 24 – Aug 21
Transplant Apr 15 – Apr 29
Fall sowing Jul 10 – Jul 24
Transplant Apr 8 – Apr 22
Fall sowing Jul 10 – Jul 24
Fall sowing Jul 10 – Jul 24
Fall sowing Aug 21 – Sep 11
Fall sowing Jul 24 – Aug 7
Plant Apr 1 – Apr 15
Based on the average last frost (Apr 29) and first frost (Oct 2). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.