Last spring frost
Apr 11
Frost Dates for South Hill, WA
First fall frost
Oct 30
Growing season
202 days
Hardiness zone
8b
In an average year around South Hill, WA, the last spring frost (32°F) is about Apr 11 and the first fall frost is about Oct 30, giving roughly a 202-day growing season. To be safe most years, wait until Mar 23 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | May 17 | May 1 | Apr 17 |
| Freeze (32°F) | Apr 29 | Apr 11 | Mar 23 |
| Hard (28°F) | Apr 8 | Mar 16 | Feb 19 |
| Severe (24°F) | Mar 16 | Feb 19 | Dec 31 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 17 | May 12 | May 7 | May 4 | May 1 | Apr 29 | Apr 26 | Apr 23 | Apr 17 |
| 32°F | Apr 29 | Apr 24 | Apr 19 | Apr 15 | Apr 11 | Apr 7 | Apr 3 | Mar 30 | Mar 23 |
| 28°F | Apr 8 | Apr 1 | Mar 27 | Mar 22 | Mar 16 | Mar 10 | Mar 4 | Feb 27 | Feb 19 |
| 24°F | Mar 16 | Mar 5 | Feb 28 | Feb 24 | Feb 19 | Feb 13 | Feb 3 | Jan 16 | Dec 31 |
| 20°F | Feb 25 | Feb 18 | Feb 10 | Feb 1 | Jan 19 | Jan 4 | Dec 30 | Dec 16 | Dec 5 |
| 16°F | Feb 17 | Feb 6 | Jan 31 | Jan 11 | Jan 2 | Dec 24 | Dec 13 | Dec 6 | Nov 30 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Sep 30 | Oct 12 | Oct 31 |
| Freeze (32°F) | Oct 13 | Oct 30 | Nov 17 |
| Hard (28°F) | Oct 28 | Nov 14 | Dec 8 |
| Severe (24°F) | Nov 8 | Dec 1 | Jan 9 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 30 | Oct 3 | Oct 5 | Oct 9 | Oct 12 | Oct 16 | Oct 19 | Oct 24 | Oct 31 |
| 32°F | Oct 13 | Oct 19 | Oct 22 | Oct 26 | Oct 30 | Nov 1 | Nov 5 | Nov 10 | Nov 17 |
| 28°F | Oct 28 | Nov 1 | Nov 6 | Nov 10 | Nov 14 | Nov 19 | Nov 24 | Nov 30 | Dec 8 |
| 24°F | Nov 8 | Nov 14 | Nov 22 | Nov 27 | Dec 1 | Dec 6 | Dec 12 | Dec 27 | Jan 9 |
| 20°F | Nov 18 | Nov 28 | Dec 2 | Dec 9 | Dec 15 | Dec 25 | Jan 1 | Jan 15 | Feb 5 |
| 16°F | Nov 23 | Dec 1 | Dec 6 | Dec 13 | Dec 22 | Jan 1 | Jan 13 | Feb 1 | Feb 12 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Mcmillin Rsvr, Wa, about 0.6 miles away@if(!empty($station['elevation_ft'])), at 579 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in South Hill, WA?
On average, the last spring frost (32°F) around South Hill, WA is about Apr 11. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 23.
When is the first frost in the fall?
The first fall frost around South Hill, WA typically arrives about Oct 30. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Apr 11 on average, or Mar 23 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 202 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 98374 Planting calendar → Washington frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026