Frost Dates for Nampa, Idaho, United States of America

Coordinates: 43.541, -116.563

Growing Season

The last spring air frost in Nampa, Idaho, United States of America typically occurs around May 17, and the first autumn air frost around Sep 12. This gives a frost-free growing season of approximately 118 days.

USDA Hardiness Zone

This location falls in USDA Hardiness Zone 7a, where the average annual extreme minimum temperature is -17.8 to -15°C (0 to 5°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 -3°C (27°F). The warmest month is July, with an average high of 34°C (93°F).

Frost Risk Breakdown

Frost dates at three temperature thresholds: Air frost (0°C / 32°F): May 17 (last spring) to Sep 12 (first autumn). Light ground frost (-1°C / 30°F): May 3 (last spring) to Sep 22 (first autumn). Hard ground frost (-2°C / 28°F): Apr 13 (last spring) to Oct 8 (first autumn).

We predict your growing zone to be approximately ...

USDA Growing Zone
USDA Growing Zone - 7a

... 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 17 to Sep 12, which provides approximately 117 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 May 3 to Sep 22, which provides a total of 142 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 12May 17
Light Ground FrostSep 22May 3
Hard Ground FrostOct 8Apr 13

Frost Dates for Nampa, Idaho, United States of America | FrostDates.com