Frost Dates for Hayward, CA
In Hayward, CA, the average last spring frost is around Jan 2 and the average first fall frost around Dec 25, for a growing season of about 365 days. For frost-tender plants, wait until Jan 27, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Hayward Air Terminal, CA weather station, 2 miles away, elevation 43 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% | Jan 27 | Dec 6 |
| 20% | Jan 18 | Dec 11 |
| 30% | Jan 12 | Dec 17 |
| 40% | Jan 7 | Dec 21 |
| 50% | Jan 2 | Dec 25 |
| 60% | Dec 31 | Dec 29 |
| 70% | Dec 27 | Jan 2 |
| 80% | Dec 22 | Jan 9 |
| 90% | Dec 13 | Jan 20 |
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) | Jan 29 | Dec 12 |
| Frost / freeze (32°F) | Jan 2 | Dec 25 |
| Hard freeze (28°F) | — | — |
Planting calendar for Hayward
Transplant Jan 9 – Jan 23
Transplant Jan 16 – Jan 30
Transplant Jan 16 – Jan 30
Transplant Jan 9 – Jan 23
Sow or transplant Jan 9 – Jan 23
Sow or transplant Jan 9 – Jan 23
Sow or transplant Jan 16 – Jan 30
Sow or transplant Dec 5 – Dec 19
Fall sowing Oct 30 – Nov 27
Fall sowing Oct 30 – Nov 20
Fall sowing Oct 16 – Oct 30
Sow or transplant Dec 5 – Dec 19
Fall sowing Oct 16 – Nov 13
Transplant Dec 19 – Jan 2
Fall sowing Oct 2 – Oct 16
Transplant Dec 12 – Dec 26
Fall sowing Oct 2 – Oct 16
Fall sowing Oct 2 – Oct 16
Fall sowing Nov 13 – Dec 4
Fall sowing Oct 16 – Oct 30
Plant Dec 5 – Dec 19
Based on the average last frost (Jan 2) and first frost (Dec 25). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.