Oxford climate

Oxford Frost Dates and Growing Season

NOAA 1991-2020 normals for Pontiac Wwtp, 20.7 km from Oxford, elevation 890 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Pontiac 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 April 26 and the first fall freeze around October 22, a growing season of about 177 days.

Median at 36°F
last May 5, first October 10
Median at 32°F
last April 26, first October 22
Median at 28°F
last April 16, first November 4

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 22May 17May 12May 8May 5May 3Apr 30Apr 27Apr 22
32°FMay 12May 5May 2Apr 29Apr 26Apr 23Apr 21Apr 18Apr 15
28°FApr 30Apr 24Apr 21Apr 18Apr 16Apr 14Apr 11Apr 7Apr 3
24°FApr 18Apr 14Apr 10Apr 6Apr 4Apr 2Mar 31Mar 28Mar 22
20°FApr 8Apr 3Apr 1Mar 29Mar 26Mar 22Mar 19Mar 16Mar 11
16°FMar 31Mar 26Mar 22Mar 19Mar 17Mar 13Mar 10Mar 6Feb 28

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 28Oct 1Oct 4Oct 7Oct 10Oct 12Oct 16Oct 19Oct 23
32°FOct 7Oct 12Oct 16Oct 20Oct 22Oct 25Oct 28Oct 31Nov 4
28°FOct 20Oct 26Oct 30Nov 1Nov 4Nov 6Nov 9Nov 13Nov 17
24°FNov 1Nov 5Nov 8Nov 11Nov 14Nov 17Nov 20Nov 24Dec 1
20°FNov 9Nov 15Nov 20Nov 23Nov 26Nov 29Dec 3Dec 8Dec 14
16°FNov 19Nov 25Nov 30Dec 3Dec 8Dec 11Dec 15Dec 20Dec 26

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°F175169164160157153149144138
32°F195190185181177173169164158
28°F218212207203200196192187180
24°F243236231226223219214210204
20°F266260254249245241236231225
16°F288281276272267262257251243

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
6,474
Cooling degree days, base 65°F
720
Growing degree days, base 40°F
4,948
Growing degree days, base 45°F
3,841
Growing degree days, base 50°F
2,869
Growing degree days, base 55°F
2,025
Growing degree days, base 60°F
1,306

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,26500
February1,08900
March923117
April543370
May22343304
June39141552
July6242700
August12206659
September11680417
October4275131
November758018
December1,07401

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 20.7 km from Oxford. 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 USC00206658 (Pontiac Wwtp). Public domain.