Brockton, Massachusetts, United States

Frost dates for Brockton

The full distribution rather than a single date. Every figure below is a percentile of 30 years of daily minimum temperatures at this location, expressed as the date it fell on.

Median last spring frost

18 April

Half of years are later than this. Not a planting date.

Median first autumn frost

3 November

The far end of the outdoor season.

Frost-free season

200 days

Between those two dates in a median year.

Last and first frost by severity

Read a row as: in this fraction of years, the last frost of spring had already happened by this date. The 90% column is the cautious planting date; the 10% column is the gamble.

Light frost — nights at or below 0°C (32°F). Air temperature reaches freezing. Kills basil, beans and unhardened tomatoes; hardy crops shrug it off.
Frost 1 year in 10 Median 9 years in 10 Earliest Latest
Last of spring 10 Apr 18 Apr 27 Apr 28 Mar 2 May
First of autumn 22 Oct 3 Nov 8 Nov 13 Oct 15 Nov
Frost-free days 212 200 178 every year on record saw this
Moderate frost — nights at or below -2.2°C (28°F). Damages half-hardy plants and most blossom. This is the threshold that decides a fruit crop.
Frost 1 year in 10 Median 9 years in 10 Earliest Latest
Last of spring 27 Mar 7 Apr 18 Apr 25 Mar 24 Apr
First of autumn 31 Oct 9 Nov 22 Nov 19 Oct 1 Dec
Frost-free days 240 216 196 every year on record saw this
Hard frost — nights at or below -4.4°C (24.1°F). Ground freezes and even hardy crops check their growth. Effectively the end of the outdoor year.
Frost 1 year in 10 Median 9 years in 10 Earliest Latest
Last of spring 12 Mar 24 Mar 7 Apr 27 Feb 17 Apr
First of autumn 9 Nov 24 Nov 12 Dec 1 Nov 27 Dec
Frost-free days 275 246 216 every year on record saw this

Dates in the southern hemisphere are computed on a growing year that starts in July, which is why "last of spring" falls where it should rather than in the middle of the calendar.

Chance of frost, week by week

Jan Mar Apr Jul Sep Oct Dec
Chance of at least one air frost during each week of the year, measured across the full record. The flat stretch in the middle is your frost-free season.

Temperature through the year

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Mean monthly temperature across the record. Months shown in blue average at least one air frost.

Monthly means and average number of frost nights.
Month Mean low Mean high Frost nights
January -6.4°C 1.7°C 27.2
February -5.8°C 2.9°C 25.3
March -2.3°C 7°C 22.4
April 2.7°C 13.2°C 6.8
May 8.4°C 19.2°C 0
June 13.8°C 24.2°C 0
July 17.7°C 28.1°C 0
August 17.2°C 28°C 0
September 13.4°C 24.2°C 0
October 7.5°C 17.3°C 1
November 1.7°C 10.5°C 11.1
December -2.9°C 4.7°C 24

Turn these dates into a planting calendar →

Nearby

Compare with places close by

Weymouth Zone 6b 17 km Last frost 18 Apr First 3 Nov Quincy Zone 6b 19 km Last frost 22 Apr First 30 Oct Taunton Zone 6b 21 km Last frost 18 Apr First 3 Nov Dorchester Zone 6b 24 km Last frost 22 Apr First 30 Oct Brookline Zone 6b 29 km Last frost 22 Apr First 30 Oct Boston Zone 6b 31 km Last frost 22 Apr First 30 Oct Newton Zone 6b 32 km Last frost 22 Apr First 30 Oct Cambridge Zone 6b 33 km Last frost 22 Apr First 30 Oct

Seasonal context

Rainfall and the growing season in Brockton

October has the highest average precipitation (123 mm); February has the lowest (85 mm). Compare this pattern with the planting windows and your water supply.

Jan 86 mm
Feb 85 mm
Mar 111 mm
Apr 110 mm
May 90 mm
Jun 108 mm
Jul 91 mm
Aug 90 mm
Sep 96 mm
Oct 123 mm
Nov 100 mm
Dec 118 mm

During wetter months, check that beds and containers drain after heavy rain. During drier months, plan how you will keep seeds and new transplants watered. Monthly averages can hide long dry spells and intense storms; they do not show soil moisture, humidity or this week's weather.

Source: NASA POWER, corrected MERRA-2 precipitation, 2001–2020. Values are approximate monthly totals, including the water equivalent of snow, from the nearest 0.5° × 0.625° grid cell. This reference period differs from the temperature record. Rainfall provides context and does not change the calculated planting dates. Method and limitations.

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