Bradford climate

Bradford Frost Dates and Growing Season

NOAA 1991-2020 normals for Dover-Foxcroft Wwtp, 23.5 km from Bradford, elevation 370 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Dover-Foxcroft Wwtp. 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 May 15 and the first fall freeze around September 28, a growing season of about 134 days.

Median at 36°F
last May 28, first September 18
Median at 32°F
last May 15, first September 28
Median at 28°F
last May 2, first October 9

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°FJun 8Jun 5Jun 2May 31May 28May 26May 23May 20May 15
32°FMay 28May 24May 20May 18May 15May 12May 8May 5Apr 30
28°FMay 16May 12May 7May 4May 2Apr 30Apr 29Apr 26Apr 22
24°FMay 5May 1Apr 28Apr 25Apr 23Apr 20Apr 18Apr 14Apr 9
20°FApr 23Apr 18Apr 15Apr 12Apr 9Apr 7Apr 5Apr 4Apr 1
16°FApr 14Apr 9Apr 7Apr 5Apr 3Apr 2Mar 31Mar 28Mar 22

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 6Sep 10Sep 13Sep 15Sep 18Sep 20Sep 23Sep 26Oct 1
32°FSep 15Sep 20Sep 23Sep 25Sep 28Sep 30Oct 2Oct 5Oct 9
28°FSep 26Sep 30Oct 3Oct 6Oct 9Oct 12Oct 15Oct 20Oct 25
24°FOct 6Oct 12Oct 16Oct 20Oct 24Oct 28Oct 31Nov 3Nov 6
20°FOct 20Oct 27Oct 31Nov 2Nov 5Nov 7Nov 11Nov 15Nov 20
16°FNov 2Nov 6Nov 10Nov 13Nov 16Nov 19Nov 22Nov 25Nov 30

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°F12912411911611310910510296
32°F153147142138134131127122116
28°F176170164161157153149144138
24°F202196191186182178174168162
20°F226220215211207204200194187
16°F244238234230227223219214209

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
8,534
Cooling degree days, base 65°F
260
Growing degree days, base 40°F
3,571
Growing degree days, base 45°F
2,641
Growing degree days, base 50°F
1,835
Growing degree days, base 55°F
1,158
Growing degree days, base 60°F
623

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,55900
February1,34500
March1,18601
April765012
May3967135
June13641358
July35111541
August5280493
September23821249
October597143
November91703
December1,30800

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 23.5 km from Bradford. 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 USC00171975 (Dover-Foxcroft Wwtp). Public domain.