Frost dates / New Hampshire / Nashua

Frost dates in Nashua, NH

The station on this page is NASHUA 2 NNW, NH US (USC00275712), 3 miles from the city point. Population in the Census 2024 estimate is 91,851.

Zone 6aUSDA average annual extreme minimum -10°F to -5°F, from ZIP 03060 (1.7 miles from the city point used on this page).

Median last 32°F is April 30. Median first 32°F is October 12. The 50% growing-season length is 165 days. The green band runs from the median last frost to the median first frost. Thin ticks mark the 10%, 50%, and 90% dates.

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Last 32°F in spring

NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.

Probability	Date	How to read it
90%	April 18	Earlier date. A last 32°F on or after this day is common.
50%	April 30	Median.
10%	May 11	Later date. A last 32°F on or after this day is uncommon.

First 32°F in fall

NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.

Probability	Date	How to read it
10%	September 30	Earlier date. A first 32°F on or before this day is uncommon.
50%	October 12	Median.
90%	October 28	Later date. A first 32°F on or before this day is common.

32°F growing-season length

Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.

Probability the season is at least this long	Days
10%	185
50%	165
90%	148

28°F threshold

	10%	50%	90%
Last, on or after	April 29	April 17	April 3
First, on or before	October 8	October 24	November 7
Season at least	209 days	190 days	172 days

36°F threshold

	10%	50%	90%
Last, on or after	May 23	May 10	April 30
First, on or before	September 21	October 2	October 15
Season at least	162 days	145 days	128 days

Station NASHUA 2 NNW, NH US (USC00275712). Completeness flag S, 26 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 100%. Freeze dates are conditional on that threshold occurring. Elevation 41.1 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

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Nashua, NH

Zone 6aAverage annual extreme minimum -10°F to -5°F

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

New Hampshire. Nearest qualified station: NASHUA 2 NNW, NH US (USC00275712), 3 miles. Median last 32°F April 30. Median first 32°F October 12. The 50% growing-season length is 165 days.

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32°F probabilities at this station

	10%	50%	90%
Last 32°F on or after	May 11	April 30	April 18
First 32°F on or before	September 30	October 12	October 28

Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.

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Planting calendar

Frost dates for New Hampshire are above. Planting windows appear for states with a cited extension guide. The fall and seed tools use the numbers you enter and the station dates.

Date checks use your device’s calendar and appear after the page loads.