Frost Dates for Renton, Washington, United States of America

Coordinates: 47.483, -122.216

Growing Season

The last spring air frost in Renton, Washington, United States of America typically occurs around May 18, and the first autumn air frost around Sep 28. This gives a frost-free growing season of approximately 133 days.

USDA Hardiness Zone

This location falls in USDA Hardiness Zone 8b, where the average annual extreme minimum temperature is -9.4 to -6.7°C (15 to 20°F). This zone rating helps gardeners determine which perennial plants are likely to survive winter.

Temperature Overview

The coldest month is February, with an average low of 2°C (36°F). The warmest month is July, with an average high of 26°C (79°F).

Frost Risk Breakdown

Frost dates at three temperature thresholds: Air frost (0°C / 32°F): May 18 (last spring) to Sep 28 (first autumn). Light ground frost (-1°C / 30°F): Apr 24 (last spring) to Oct 17 (first autumn). Hard ground frost (-2°C / 28°F): Mar 13 (last spring) to Nov 24 (first autumn).

We predict your growing zone to be approximately ...

USDA Growing Zone
USDA Growing Zone - 8b

... and the frost data for your area is ...

Current Risk Level: Light Ground Frost possible

for today based on past data only.

We predict a frost free growing season at your location from May 18 to Sep 28, which provides approximately 132 frost free days.

For the less tender plants, or if you are planning to protect your plants with fleece etc, your growing season could stretch from Apr 24 to Oct 17, which provides a total of 176 days for growing.

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
  • Hard Ground Frost possible
  • Light Ground Frost possible
  • Air Frost possible
  • Safest (unlikely)
First and last frost dates by frost type
FirstLast
Air FrostSep 28May 18
Light Ground FrostOct 17Apr 24
Hard Ground FrostNov 24Mar 13

Frost Dates for Renton, Washington, United States of America | FrostDates.com