Manchester, New Hampshire: freeze dates & growing season

Three different things get called “Manchester” here, so this page is explicit about all three: the metro label (Manchester), the anchor geography (Census ZCTA 03101, a downtown ZIP-code area), and the climate record (the NOAA station below). Windows are calculated from the station — not from your street address.

Climate basis: NOAA station Massabesic Lake, NH (USC00275211), 4 mi (6 km) from the ZCTA 03101 centroid, elevation 253 ft, on the 1991–2020 climate normals.

Last spring freezeApril 301-in-10 after May 14

First fall freezeOctober 111-in-10 before Sep 30

Frost-free season≈ 164 daysmedian at 32°F

Hard freeze, 28°Apr 17 – Oct 24kills even hardy greens

USDA zone6a-10 to -5°F winter low — not frost timing

The year

indoors under lights
in the garden
frost-free season
1-in-10 years still freeze to May 14

The Manchester year: hatched areas are the freeze-likely seasons in 1991–2020 normals.

What that means in practice

Tomatoes: plant May 7 – May 21
Peas: plant March 19 – April 2
Garlic: plant cloves October 18 – October 25

All 79 crops in Manchester

These windows describe typical years (1991–2020 climate normals), not this year's forecast. Freezes happen outside them — especially in frost pockets, valleys, and urban edges. Watch the forecast before committing tender plants.

Check a specific ZIP instead

Metro climates vary — elevation, water, and urban heat shift freeze dates by days to weeks. Look up your exact ZIP:

Nearby reviewed metros

Boston, MA · Portland, ME · Providence, RI · Hartford, CT · Burlington, VT