Frost dates in Bellevue, Washington
NOAA 1991–2020 normals for a 32 °F freeze. Low spots and the edge of town run colder than downtown.
Short answer
The average last spring frost in Bellevue is March 8, and the average first fall frost is November 23, from NOAA's Seattle Sand Pt Wsfo station, 8 miles from the middle of Bellevue. 1 year in 10 the last frost comes after March 29, and the first one by November 4. That leaves about 260 frost-free days. Bellevue is in USDA planting zone 9a.
Weather stations around Bellevue
The first row is the date most people in Bellevue go by. The others show how far the dates move across the area.
| Station | Last spring frost | First fall frost | Frost-free |
|---|---|---|---|
| Seattle Sand Pt Wsfo 8 mi away, 60 ft | March 8 1 in 10 after March 29 | November 23 1 in 10 by November 4 | 260 days |
| Renton Muni Airport 8 mi away, 29 ft | March 13 1 in 10 after March 31 | November 16 1 in 10 by October 29 | 248 days |
| Seattle Boeing Fld 8 mi away, 20 ft | March 13 1 in 10 after April 1 | November 17 1 in 10 by November 1 | 249 days |
| Seattle Tacoma Intl Airport 13 mi away, 370 ft | March 2 1 in 10 after March 23 | November 23 1 in 10 by November 6 | 266 days |
| Kent 13 mi away, 30 ft | March 20 1 in 10 after April 8 | November 10 1 in 10 by October 26 | 235 days |
Distances are from the middle of Bellevue as the Census Bureau maps it. The average date is NOAA's 50% date: half of years have a later last frost, or an earlier first one. Plan by the 1-in-10 date if a freeze would cost you plants. The planting zone is the USDA 2023 zone for ZIP code 98005, at the middle of the city.
Your exact ZIP code
Bellevue covers a lot of ground. For the station nearest your own street, and its planting zone, type your ZIP code.
How these dates work
Frost dates come from NOAA's 1991 to 2020 Climate Normals, which work out from each weather station's daily lows how likely the last spring freeze and the first fall freeze (32 °F) are by each date. We use the station nearest the middle of your ZIP code and show its height and distance, since a station on a hill or by a lake can differ from your yard.
The average date is the 50% date: half of years have a freeze after the spring date or before the fall one. The 1-in-10 dates are NOAA's 10% dates, the ones to plan by if a late freeze would cost you plants. Within one yard, cold air pools in low spots while walls and paving hold heat, so some corners freeze before others.
More frost dates
All of Washington, station by station.
Other Washington cities: Seattle · Spokane · Tacoma · Vancouver
Nearby: Portland, OR
Where the numbers come from
- USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture
- PRISM Climate Group, Oregon State University (zone data)
- NOAA NCEI, U.S. Climate Normals 1991–2020, annual/seasonal
- NOAA, Normals calculation methodology (frost-freeze probability dates)
- US Census Bureau, 2025 ZCTA gazetteer (ZIP code centers)
- US Census Bureau, 2025 city population estimates and place gazetteer