Mild planning load. A standardized data profile for planning an outdoor traditional sauna in the Seattle area.
0 months with normal minimum below 32°F
0 in modeled/observed normal snow in the current record
36.5 in annual precipitation
Climate source: NOAA/NCEI U.S. Monthly Climate Normals 1991–2020 (direct by-station archive)
Station: USW00024234 — SEATTLE BOEING FLD (4.5 mi from city reference point)
In colder locations, the enclosure starts farther from sauna temperature, making insulation, door discipline, glass area and heater sizing more consequential. The city score is designed to compare that planning burden—not to dictate a particular heater.
At the current state electricity input, the standardized 9 kW scenario is approximately $2.18 per session, or about $340/year at three sessions per week. Your actual use can differ materially.
Calculate effective room volume Where to buy an outdoor sauna