When is the last frost in New Plymouth, ID?

The average last spring frost date in New Plymouth, ID is Apr 27. This is when it is generally safe to plant frost-sensitive vegetables and flowers outdoors.

When is the first frost in New Plymouth, ID?

The average first fall frost date in New Plymouth, ID is Oct 14. Plan to harvest frost-sensitive crops before this date.

How long is the growing season in New Plymouth, ID?

The growing season in New Plymouth, ID is approximately 169 days, measured from the last spring frost to the first fall frost.

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Frost Dates for New Plymouth, ID

Location New Plymouth, ID

Frost Dates

New Plymouth, ID

Use our 2026 Frost Dates Calculator to find the first fall frost and last spring frost dates for your area, based on historical climate data from the weather station nearest your ZIP or Postal Code. These dates help you estimate your growing season and plan spring planting, fall harvesting, and frost protection.

Nearest Climate Station	Altitude	Last Spring Frost	First Fall Frost	Growing Season
PAYETTE, ID	2148'	Apr 27	Oct 14	169 days

Last and first frost dates are 30% probability. Calculated using 1991-2020 Climate Normals from NOAA.

Our frost dates are based on 1991–2020 climate data from the National Oceanic and Atmospheric Administration (NOAA). We use a 30% probability threshold, meaning there’s about a 3 in 10 chance frost will occur before or after the given date. Because microclimates vary—your backyard might be warmer or cooler than nearby towns—use these dates as a flexible guide, not a guarantee.