Bedford climate

Bedford Frost Dates and Growing Season

NOAA 1991-2020 normals for Arlington Six Flags, 11.6 km from Bedford, elevation 536 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Arlington Six Flags. 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 March 9 and the first fall freeze around November 20, a growing season of about 253 days.

Median at 36°F
last March 25, first November 8
Median at 32°F
last March 9, first November 20
Median at 28°F
last February 26, first December 3

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 15Apr 7Apr 3Mar 30Mar 25Mar 20Mar 14Mar 9Mar 2
32°FApr 2Mar 25Mar 18Mar 13Mar 9Mar 5Mar 1Feb 26Feb 19
28°FMar 16Mar 10Mar 6Mar 1Feb 26Feb 22Feb 18Feb 12Feb 2
24°FMar 8Mar 1Feb 24Feb 17Feb 12Feb 6Jan 31Jan 27Jan 15
20°FFeb 28Feb 16Feb 9Feb 5Jan 31Jan 25Jan 18Jan 9Dec 29
16°FFeb 16Feb 8Feb 3Jan 29Jan 21Jan 16Jan 7Jan 1Dec 20

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 24Oct 29Nov 1Nov 5Nov 8Nov 12Nov 16Nov 22Nov 30
32°FOct 31Nov 5Nov 10Nov 15Nov 20Nov 25Dec 1Dec 4Dec 10
28°FNov 10Nov 19Nov 25Nov 30Dec 3Dec 6Dec 11Dec 17Dec 25
24°FNov 22Dec 1Dec 5Dec 11Dec 16Dec 22Dec 28Jan 2Jan 16
20°FDec 6Dec 13Dec 22Dec 28Jan 1Jan 6Jan 13Jan 22Feb 5
16°FDec 13Dec 24Dec 31Jan 3Jan 10Jan 17Jan 24Feb 1Feb 9

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°F256247241234229224218212203
32°F280271263258253247240233223
28°F311301293285280272266258250
24°F343331323316309302294285273
20°F365365356347338333325316302
16°F365365365365365362352341329

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
98% of years
20°F or colder
80% of years
16°F or colder
47% 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
2,481
Cooling degree days, base 65°F
2,566
Growing degree days, base 40°F
9,357
Growing degree days, base 45°F
7,716
Growing degree days, base 50°F
6,204
Growing degree days, base 55°F
4,837
Growing degree days, base 60°F
3,622

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January632154
February462495
March28523250
April10577428
May16245695
June0474924
July06121,077
August06001,065
September6379823
October89126507
November31921210
December568476

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 11.6 km from Bedford. 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 USC00410337 (Arlington Six Flags). Public domain.