Frost Report

All states Connecticut

Frost dates for Danbury, CT

When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.

Last spring frost

May 1

typical year

Safe to plant

May 16

frost is over in 9 of 10 years

First fall frost

October 14

typical year

Growing season

166 days

frost-free, typical year

When to plant

Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.

CropStart indoorsPlant outsideFall planting
Cool-season crops
Peas – Apr 3 – 17 –
Spinach – Mar 20 – Apr 10 Aug 19 – Sep 2
Lettuce – Apr 3 – 24 Aug 19 – Sep 2
Radishes – Apr 3 – May 15 Sep 2 – 16
Onions – Apr 3 – 17 –
Potatoes – Apr 10 – 24 –
Carrots – Apr 10 – May 1 Jul 22 – Aug 5
Beets – Apr 3 – 17 Aug 5 – 19
Kale Feb 20 – Mar 6 Apr 3 – 17 Aug 5 – 19
Broccoli Feb 20 – Mar 6 Apr 17 – May 1 Aug 5 – 19
Cabbage Feb 6 – 20 Apr 3 – 17 Aug 5 – 19
Garlic – – Sep 2 – 23
Warm-season crops
Tomatoes Mar 21 – Apr 4 May 16 – 30 –
Peppers Mar 14 – 28 May 23 – Jun 6 –
Cucumbers – May 16 – Jun 6 –
Zucchini – May 16 – Jun 13 –
Pumpkins – May 16 – Jun 6 –
Green beans – May 16 – Aug 5 –
Sweet corn – May 16 – Jun 13 –
Basil Apr 11 – 25 May 23 – 30 –

Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.

The year at a glance

Start indoors Plant outside Fall planting

The chance of frost, by date

1 year in 10Half of years9 years in 10
Spring frost after May 16May 1April 18
Fall frost before October 1October 14October 29

Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.

Hard freeze (28°F)

A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around April 18 (May 4 in a late year), and the first one in fall around October 27.

Towns that use these dates

This is the nearest NOAA station with frost records for 1 town.

Danbury

Where these dates come from

NOAA weather station DANBURY MUNI AP, CT US (USW00054734), 1991–2020 climate normals. It's the nearest station for 8 zip codes, all within 12 miles:

06810, 06877, 06883, 06896, 10518, 10560, 10590, 10597

Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.