Frost Dates for Joliet, Illinois, United States of America

Coordinates: 41.525, -88.082

Growing Season

The last spring air frost in Joliet, Illinois, United States of America typically occurs around Apr 25, and the first autumn air frost around Sep 23. This gives a frost-free growing season of approximately 151 days.

USDA Hardiness Zone

This location falls in USDA Hardiness Zone 5b, where the average annual extreme minimum temperature is -26.1 to -23.3°C (-15 to -10°F). This zone rating helps gardeners determine which perennial plants are likely to survive winter.

Temperature Overview

The coldest month is January, with an average low of -8°C (18°F). The warmest month is July, with an average high of 28°C (82°F).

Frost Risk Breakdown

Frost dates at three temperature thresholds: Air frost (0°C / 32°F): Apr 25 (last spring) to Sep 23 (first autumn). Light ground frost (-1°C / 30°F): Apr 16 (last spring) to Oct 2 (first autumn). Hard ground frost (-2°C / 28°F): Apr 1 (last spring) to Oct 16 (first autumn).

We predict your growing zone to be approximately ...

USDA Growing Zone
USDA Growing Zone - 5b

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

Current Risk Level: Air Frost possible

for today based on past data only.

We predict a frost free growing season at your location from Apr 25 to Sep 23, which provides approximately 150 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 16 to Oct 2, which provides a total of 169 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 23Apr 25
Light Ground FrostOct 2Apr 16
Hard Ground FrostOct 16Apr 1

Frost Dates for Joliet, Illinois, United States of America | FrostDates.com