Oxford climate

Oxford Frost Dates and Growing Season

NOAA 1991-2020 normals for Salem, 18.8 km from Oxford, elevation 680 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Salem. 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 8 and the first fall freeze around October 30, a growing season of about 204 days.

Median at 36°F
last April 20, first October 20
Median at 32°F
last April 8, first October 30
Median at 28°F
last March 29, first November 8

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 5Apr 30Apr 27Apr 24Apr 20Apr 17Apr 14Apr 10Apr 5
32°FApr 25Apr 19Apr 15Apr 11Apr 8Apr 4Apr 2Mar 29Mar 22
28°FApr 13Apr 8Apr 4Apr 1Mar 29Mar 25Mar 19Mar 15Mar 8
24°FApr 3Mar 29Mar 23Mar 18Mar 15Mar 12Mar 7Mar 3Feb 26
20°FMar 25Mar 17Mar 13Mar 8Mar 4Feb 28Feb 25Feb 20Feb 10
16°FMar 14Mar 7Mar 2Feb 26Feb 21Feb 17Feb 11Feb 4Jan 27

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 7Oct 12Oct 15Oct 17Oct 20Oct 22Oct 24Oct 27Oct 31
32°FOct 18Oct 22Oct 24Oct 27Oct 30Nov 1Nov 2Nov 6Nov 12
28°FOct 27Nov 1Nov 3Nov 5Nov 8Nov 11Nov 15Nov 19Nov 26
24°FNov 3Nov 7Nov 11Nov 15Nov 19Nov 23Nov 28Dec 1Dec 6
20°FNov 11Nov 18Nov 24Nov 27Dec 1Dec 4Dec 8Dec 13Dec 21
16°FNov 24Nov 30Dec 4Dec 10Dec 15Dec 20Dec 24Dec 31Jan 7

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°F201194190186182178173169162
32°F225217212208204200195190184
28°F250242235231226222217211203
24°F273265259254249243238232223
20°F296287281275270265259252243
16°F326315307301295289281274265

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
4,182
Cooling degree days, base 65°F
1,480
Growing degree days, base 40°F
7,008
Growing degree days, base 45°F
5,608
Growing degree days, base 50°F
4,353
Growing degree days, base 55°F
3,246
Growing degree days, base 60°F
2,290

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January921013
February727127
March537597
April25027258
May79107495
June3297744
July0423888
August1397862
September34184600
October23735285
November548371
December846014

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 18.8 km from Oxford. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00036403 (Salem). Public domain.