Mayflower climate

Mayflower Frost Dates and Growing Season

NOAA 1991-2020 normals for Marche, 11.1 km from Mayflower, elevation 272 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Marche. 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 1 and the first fall freeze around November 1, a growing season of about 213 days.

Median at 36°F
last April 13, first October 21
Median at 32°F
last April 1, first November 1
Median at 28°F
last March 17, first November 11

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°FApr 28Apr 22Apr 19Apr 15Apr 13Apr 10Apr 7Apr 4Mar 29
32°FApr 17Apr 11Apr 7Apr 4Apr 1Mar 29Mar 25Mar 19Mar 13
28°FApr 5Apr 1Mar 27Mar 22Mar 17Mar 14Mar 10Mar 5Feb 28
24°FMar 22Mar 16Mar 11Mar 7Mar 3Feb 28Feb 25Feb 20Feb 12
20°FMar 12Mar 5Feb 28Feb 25Feb 19Feb 13Feb 7Feb 1Jan 23
16°FMar 1Feb 23Feb 15Feb 8Feb 3Jan 29Jan 23Jan 15Jan 4

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°FOct 9Oct 13Oct 16Oct 19Oct 21Oct 24Oct 26Oct 29Nov 2
32°FOct 19Oct 23Oct 26Oct 29Nov 1Nov 3Nov 6Nov 9Nov 15
28°FOct 30Nov 2Nov 5Nov 8Nov 11Nov 14Nov 18Nov 22Nov 27
24°FNov 5Nov 11Nov 15Nov 19Nov 22Nov 26Dec 1Dec 5Dec 12
20°FNov 16Nov 22Nov 27Dec 1Dec 7Dec 11Dec 19Dec 25Jan 4
16°FNov 29Dec 5Dec 14Dec 22Dec 29Jan 2Jan 8Jan 15Jan 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°F208202198194190186182178171
32°F236228222218213209204199192
28°F263255248242237232227221212
24°F292282274268262258252246238
20°F327318308301294287280272260
16°F362351340333325318310303290

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
99% of years
16°F or colder
92% 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
3,511
Cooling degree days, base 65°F
1,814
Growing degree days, base 40°F
7,758
Growing degree days, base 45°F
6,253
Growing degree days, base 50°F
4,907
Growing degree days, base 55°F
3,718
Growing degree days, base 60°F
2,692

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January824013
February626043
March4384121
April19328301
May42163586
June0365814
July0497962
August0451916
September16239673
October18164360
November471396
December719023

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 11.1 km from Mayflower. 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 USC00034625 (Marche). Public domain.