Orange climate

Orange Frost Dates and Growing Season

NOAA 1991-2020 normals for Piedmont Rsch Stn, 1.6 km from Orange, elevation 520 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Piedmont Rsch Stn. 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 7 and the first fall freeze around October 30, a growing season of about 204 days.

Median at 36°F
last April 21, first October 21
Median at 32°F
last April 7, first October 30
Median at 28°F
last March 27, 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 9May 3Apr 29Apr 24Apr 21Apr 18Apr 14Apr 11Apr 6
32°FApr 26Apr 19Apr 14Apr 10Apr 7Apr 4Apr 1Mar 29Mar 24
28°FApr 11Apr 5Apr 1Mar 31Mar 27Mar 24Mar 21Mar 17Mar 12
24°FMar 31Mar 27Mar 23Mar 20Mar 17Mar 14Mar 11Mar 6Feb 28
20°FMar 22Mar 18Mar 14Mar 10Mar 6Mar 3Feb 28Feb 23Feb 15
16°FMar 16Mar 10Mar 4Feb 28Feb 24Feb 17Feb 10Feb 5Jan 30

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 18Oct 21Oct 24Oct 26Oct 28Nov 1
32°FOct 17Oct 22Oct 25Oct 28Oct 30Nov 1Nov 4Nov 8Nov 13
28°FOct 27Oct 31Nov 2Nov 5Nov 8Nov 11Nov 15Nov 19Nov 26
24°FNov 5Nov 10Nov 14Nov 18Nov 22Nov 26Dec 1Dec 5Dec 13
20°FNov 17Nov 24Nov 29Dec 3Dec 7Dec 12Dec 18Dec 23Jan 1
16°FDec 1Dec 9Dec 14Dec 20Dec 24Dec 29Jan 2Jan 8Jan 18

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°F200194189185180177173167160
32°F224216211207204199195189181
28°F251242236231226223219212207
24°F276267259255250245241235227
20°F304295289283277271266259251
16°F330321312307302297291284274

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
4,425
Cooling degree days, base 65°F
1,199
Growing degree days, base 40°F
6,490
Growing degree days, base 45°F
5,124
Growing degree days, base 50°F
3,912
Growing degree days, base 55°F
2,853
Growing degree days, base 60°F
1,950

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January934011
February764014
March624262
April30722212
May11384437
June13240676
July0363828
August1314778
September41150560
October26222249
November544169
December820017

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 1.6 km from Orange. 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 USC00446712 (Piedmont Rsch Stn). Public domain.