Hanson climate

Hanson Frost Dates and Growing Season

NOAA 1991-2020 normals for Brockton, 11 km from Hanson, elevation 75 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Brockton. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around April 22 and the first fall freeze around October 19, a growing season of about 178 days.

Median at 36°F
last May 5, first October 7
Median at 32°F
last April 22, first October 19
Median at 28°F
last April 6, first October 31

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FMay 18May 13May 10May 8May 5May 3May 1Apr 28Apr 24
32°FMay 5May 1Apr 28Apr 25Apr 22Apr 20Apr 17Apr 13Apr 8
28°FApr 20Apr 17Apr 13Apr 9Apr 6Apr 4Apr 2Mar 31Mar 27
24°FApr 8Apr 4Apr 1Mar 30Mar 27Mar 24Mar 21Mar 17Mar 12
20°FMar 31Mar 27Mar 23Mar 20Mar 17Mar 14Mar 11Mar 8Mar 3
16°FMar 23Mar 18Mar 14Mar 11Mar 8Mar 5Mar 1Feb 26Feb 19

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FSep 26Sep 30Oct 2Oct 5Oct 7Oct 10Oct 13Oct 17Oct 22
32°FOct 5Oct 9Oct 13Oct 16Oct 19Oct 22Oct 25Oct 28Nov 3
28°FOct 16Oct 20Oct 25Oct 28Oct 31Nov 2Nov 6Nov 10Nov 15
24°FOct 29Nov 2Nov 6Nov 10Nov 12Nov 16Nov 19Nov 25Dec 1
20°FNov 12Nov 16Nov 20Nov 25Nov 29Dec 1Dec 4Dec 8Dec 14
16°FNov 25Dec 1Dec 3Dec 6Dec 9Dec 13Dec 18Dec 22Dec 28

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F172166163159155151148144139
32°F198191187183178173169165158
28°F226218213208205200196192184
24°F253245239234230226221216210
20°F277269264258254251245240233
16°F299292286281277272267262254

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
5,673
Cooling degree days, base 65°F
773
Growing degree days, base 40°F
5,234
Growing degree days, base 45°F
4,026
Growing degree days, base 50°F
2,982
Growing degree days, base 55°F
2,095
Growing degree days, base 60°F
1,359

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,09602
February94102
March827013
April499476
May22929275
June49130531
July4277738
August8238696
September9386444
October3669161
November635139
December92806

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 11 km from Hanson. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00190860 (Brockton). Public domain.