Last spring freeze
Mar 13
median (50%)
8 in 10 years Feb 20 – Apr 1
Only a 1-in-10 chance of a freeze after Apr 1.
Seattle, WA · NOAA frost dates
Seattle frost dates & planting calendar
Last spring freeze ~Mar 13, first fall freeze ~Nov 17: a median of 249 frost-free days. The calendar below is already set to Seattle (ZIP 98101). Type your own ZIP for the station nearest you.
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Seattle, WA · ZIP 98101 · try yours
Seattle WA area
Last spring frost
~Mar 13
safer: Apr 1
First fall frost
~Nov 17
safer: Nov 1
Growing season
249
frost-free days
- Start indoors
- Sow outside
- Transplant
- Fall planting
- Harvest
Median dates from NOAA 1991–2020 climate normals. Averages, not forecasts. How it works
NOAA 1991–2020 climate normals
Seattle frost dates at a glance
32°F freeze dates for the Seattle Boeing Fld, WA weather station, 9 km from ZIP 98101, 6 m up.
First fall freeze
Nov 17
median (50%)
8 in 10 years Nov 1 – Dec 6
Only a 1-in-10 chance of a freeze before Nov 1.
Growing season
249
median frost-free days
USDA zone 9a
Station: Seattle Boeing Fld, WA
Long-term averages, not a forecast. Your yard can run one to three weeks off these dates, so check the 10-day forecast before planting out.
Source: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991–2020 (32°F freeze probabilities: 10%, 50%, 90%). Public domain. How we use it
Planting dates for Seattle
When to plant in Seattle
Worked out from the median frost dates (and, for warm-season crops, NOAA’s normal night lows) with the same crop rules as the calendar below. Tap any crop there for its dates.
-
Tomatoes
- Start indoors
- Mar 17 – Mar 31
- Transplant out
- May 19 – Jun 9
Frost alone would allow transplanting from Mar 20, but the normal night low here only reaches 50°F (10°C) about May 19, so they go out then, started indoors 9 weeks before. Transplant when nights stay above 50°F (10°C).
-
Peppers
- Start indoors
- Feb 24 – Mar 10
- Transplant out
- May 19 – Jun 2
Frost alone would allow transplanting from Mar 27, but the normal night low here only reaches 50°F (10°C) about May 19, so they go out then, started indoors 12 weeks before. Loves warm soil, 65°F+ (18°C+).
-
Peas
- Sow outside
- Jan 30 – Feb 20
- Fall sowing
- Sep 8 – Sep 22
3–6 weeks before the last frost, and again 8–10 weeks before the first fall frost. Sow as soon as soil can be worked (40°F/4°C+).
-
Lettuce
- Sow outside
- Feb 13 – Mar 27
- Fall sowing
- Sep 22 – Oct 20
From 4 weeks before to 2 weeks after the last frost, and 4–8 weeks before the first fall frost. Bolts in heat; sow small batches often.
-
Garlic
- Plant cloves
- Nov 3 – Dec 8
- Harvest
- May 15 – Jun 5, next year
2 weeks before to 3 weeks after the first fall frost. Plant cloves in fall; harvest next summer when lower leaves brown.
This week
Right now in your garden
Full year
Your planting calendar
- Start indoors
- Sow outside
- Transplant
- Fall sowing / planting
- Harvest
- Harvest the season after planting
- Est. frost date
No crops match. Try another search, or clear “My picks”.
Tap ☆ to add a crop to your picks. Tap a crop name for exact dates and growing notes. Your picks and location are saved on this device.
Straight answers
Frost questions
When is the last frost in Seattle?
The median last spring freeze (32°F) at NOAA’s Seattle Boeing Fld, WA station is Mar 13, based on 1991–2020 climate normals. In 8 of 10 years it falls between Feb 20 and Apr 1, and there is only a 1-in-10 chance of a freeze after Apr 1.
When is the first fall frost in Seattle?
The median first fall freeze (32°F) is Nov 17. In 8 of 10 years it falls between Nov 1 and Dec 6, and there is only a 1-in-10 chance of a freeze before Nov 1. That leaves a median of 249 frost-free days.
When should I plant tomatoes in Seattle?
Using FrostLine’s crop rules with the median last frost of Mar 13 and NOAA’s normal night lows: start tomato seeds indoors Mar 17 – Mar 31 and transplant them outside May 19 – Jun 9. Frost alone would allow Mar 20, but nights here only average 50°F (10°C) from about May 19.
Are these dates a forecast?
No. They are long-term averages, not a forecast for this year. Your own garden can differ by one to three weeks with elevation, slope, wind and how built-up it is. Check the 10-day forecast before setting out tender plants, and enter your own ZIP for the nearest station.
How it works: each ZIP is matched to the nearest NOAA station with freeze records. More on our method.
Frost dates by city
More frost dates by city
Each page opens the same free calendar, set to that city. Or start from the home page.
- CO · zone 6a Denver Last frost ~Apr 30First frost ~Oct 12 165 frost-free days
- IL · zone 6b Chicago Last frost ~Apr 10First frost ~Nov 5 209 frost-free days
- GA · zone 8a Atlanta Last frost ~Mar 24First frost ~Nov 8 229 frost-free days
- TX · zone 8a Dallas Last frost ~Mar 2First frost ~Nov 29 272 frost-free days
- MN · zone 4b Minneapolis Last frost ~Apr 23First frost ~Oct 16 176 frost-free days
- OR · zone 8b Portland Last frost ~Feb 25First frost ~Dec 1 279 frost-free days
- MA · zone 7a Boston Last frost ~Apr 4First frost ~Nov 9 219 frost-free days
- TN · zone 7a Nashville Last frost ~Apr 1First frost ~Oct 31 213 frost-free days
- UT · zone 7a Salt Lake City Last frost ~Mar 31First frost ~Nov 8 222 frost-free days