YepPlant

Frost Dates and Planting Windows in Washington

The 32°F frost dates at the 154 weather stations in Washington with NOAA's 1991–2020 Climate Normals, and the planting windows they give. These are long-term statistics, not a forecast. For the dates at the station nearest you, enter your ZIP code.

The planner uses the weather station nearest your ZIP code.

Frost dates across Washington

Each risk level uses a date with a set chance of frost. In spring, it's the chance of a 32°F frost on or after the last-frost date. In fall, it's the chance of the first 32°F frost on or before the first-frost date. At the Typical level (30%), the last frost ranges from March 9 to June 17 across the state, and the first frost from August 30 to November 21.

At 4 of these 154 stations, 32°F isn't reached every year. Their frost dates describe only the years when it is reached, and the ranges on this page include them.

32°F frost dates: earliest and latest among 154 stations, by risk level
Risk levelEarliest last frostLatest last frostEarliest first frostLatest first frost
Conservative (10%)March 233 stationsJuly 13SPOKANE 17 SSW, WA USAugust 21SPOKANE 17 SSW, WA USNovember 10OLGA 2 SE, WA US
Typical (30%)March 9OLGA 2 SE, WA USJune 17DAVENPORT, WA USAugust 30SPOKANE 17 SSW, WA USNovember 21OLGA 2 SE, WA US
Aggressive (50%)February 26OLGA 2 SE, WA USJune 6DAVENPORT, WA USSeptember 4SPOKANE 17 SSW, WA USNovember 29OLGA 2 SE, WA US

Growing season length

The growing season is the stretch between the last spring frost and the first fall frost at 32°F. NOAA gives it as a length with a chance of being at least that long. Each risk level uses the length with that chance of a shorter season, so Conservative shows the shortest lengths.

Growing season at 32°F: shortest and longest among 154 stations
Risk levelShortestLongest
Conservative (90% chance of at least this long)56 daysSPOKANE 17 SSW, WA US243 daysPORT TOWNSEND, WA US
Typical (70% chance of at least this long)79 daysSPOKANE 17 SSW, WA US262 daysOLGA 2 SE, WA US
Aggressive (50% chance of at least this long)94 days2 stations276 daysOLGA 2 SE, WA US
Number of stations by growing season length, Typical (70% chance of at least this long)
Growing seasonStations
60–79 days1
80–99 days4
100–119 days8
120–139 days15
140–159 days31
160–179 days33
180–199 days23
200–219 days23
220–239 days9
240–259 days5
260–279 days2

Planting windows across Washington

For each crop, the earliest start and the latest end of its Typical windows among the stations. A window at any one station is shorter and falls inside this span. Transplant dates are for seedlings. A fall window is left out at stations where it would start on or before the last day of the spring window, so some rows cover fewer stations.

Typical planting windows (30% frost dates): earliest start and latest end among stations
Crop and taskEarliest startLatest endStations
Basil: Transplant outdoorsMarch 23July 1154 of 154
Bean: Sow outdoorsMarch 9June 17154 of 154
Beet: Sow outdoorsFebruary 9June 17154 of 154
Beet: Sow for fallJune 12October 2152 of 154
Broccoli: Transplant outdoorsFebruary 9June 3154 of 154
Broccoli: Transplant for fallJune 2October 2152 of 154
Brussels sprouts: Transplant outdoorsFebruary 9June 3154 of 154
Brussels sprouts: Transplant for fallMay 17October 12148 of 154
Cabbage: Transplant outdoorsFebruary 9June 3154 of 154
Cabbage: Transplant for fallMay 28October 2152 of 154
Cantaloupe: Transplant outdoorsMarch 23July 1154 of 154
Cantaloupe: Sow outdoorsMarch 23July 1154 of 154
Carrot: Sow outdoorsFebruary 9June 17154 of 154
Carrot: Sow for fallJune 5September 22150 of 154
Cucumber: Transplant outdoorsMarch 16June 24154 of 154
Cucumber: Sow outdoorsMarch 9June 17154 of 154
Eggplant: Transplant outdoorsMarch 23July 1154 of 154
Garlic: Plant for fallAugust 30December 5154 of 154
Lettuce: Transplant outdoorsFebruary 9June 3154 of 154
Lettuce: Sow outdoorsFebruary 9June 3154 of 154
Lettuce: Sow for fallJune 2October 12152 of 154
Onion: Transplant or plant setsFebruary 9June 3154 of 154
Peas: Sow outdoorsFebruary 9June 3154 of 154
Peas: Sow for fallJune 5October 2154 of 154
Pepper: Transplant outdoorsMarch 23July 1154 of 154
Potato: Plant seed potatoesFebruary 9June 17154 of 154
Pumpkin: Sow outdoorsMarch 23July 1154 of 154
Radish: Sow outdoorsFebruary 9June 3154 of 154
Radish: Sow for fallJuly 12November 1154 of 154
Spinach: Transplant outdoorsFebruary 9June 3154 of 154
Spinach: Sow outdoorsFebruary 9June 3154 of 154
Spinach: Sow for fallJune 17October 15154 of 154
Summer squash: Transplant outdoorsMarch 16June 24154 of 154
Summer squash: Sow outdoorsMarch 9June 17154 of 154
Sweet corn: Sow outdoorsMarch 9June 17154 of 154
Sweet potato: Plant slipsMarch 16July 1154 of 154
Tomato: Transplant outdoorsMarch 23July 1154 of 154
Turnip: Sow outdoorsFebruary 9June 3154 of 154
Turnip: Sow for fallJune 17October 12154 of 154
Watermelon: Transplant outdoorsMarch 23July 1154 of 154
Watermelon: Sow outdoorsMarch 23July 1154 of 154

Weather stations in Washington

Every station in Washington with NOAA frost-date normals, with its Typical 32°F frost dates and growing season. 2 of them have no 32°F frost dates.

Data sources

NOAA U.S. Climate Normals, frost dates, 1991–2020 normals, version 1.0.1
Files: us-climate-normals_1991-2020_v1.0.1_annualseasonal_multivariate_by-station_c20230404.tar.gz, inventory_30yr.txt from NOAA NCEI. Retrieved October 10, 2026.