Frost Dates for Rexburg, ID
In Rexburg, ID, the average last spring frost is around May 12 and the average first fall frost around Sep 24, for a growing season of about 132 days. For frost-tender plants, wait until Jun 2, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Rexburg Byu Idaho, ID weather station, under 1 mile away, elevation 5,005 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% | Jun 2 | Sep 6 |
| 20% | May 27 | Sep 12 |
| 30% | May 20 | Sep 17 |
| 40% | May 15 | Sep 21 |
| 50% | May 12 | Sep 24 |
| 60% | May 9 | Sep 27 |
| 70% | May 6 | Oct 1 |
| 80% | May 3 | Oct 4 |
| 90% | Apr 29 | Oct 8 |
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) | Jun 4 | Sep 11 |
| Frost / freeze (32°F) | May 12 | Sep 24 |
| Hard freeze (28°F) | Apr 30 | Oct 7 |
Planting calendar for Rexburg
Transplant May 19 – Jun 2
Transplant May 26 – Jun 9
Transplant May 26 – Jun 9
Transplant May 19 – Jun 2
Sow or transplant May 19 – Jun 2
Sow or transplant May 19 – Jun 2
Sow or transplant May 26 – Jun 9
Sow or transplant Apr 14 – Apr 28
Fall sowing Jul 30 – Aug 27
Fall sowing Jul 30 – Aug 20
Fall sowing Jul 16 – Jul 30
Sow or transplant Apr 14 – Apr 28
Fall sowing Jul 16 – Aug 13
Transplant Apr 28 – May 12
Fall sowing Jul 2 – Jul 16
Transplant Apr 21 – May 5
Fall sowing Jul 2 – Jul 16
Fall sowing Jul 2 – Jul 16
Fall sowing Aug 13 – Sep 3
Fall sowing Jul 16 – Jul 30
Plant Apr 14 – Apr 28
Based on the average last frost (May 12) and first frost (Sep 24). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.