Granite Falls climate

Granite Falls Frost Dates and Growing Season

NOAA 1991-2020 normals for Hickory FAA AP, 7.5 km from Granite Falls, elevation 1143 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hickory FAA AP. 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 31 and the first fall freeze around November 4, a growing season of about 219 days.

Median at 36°F
last April 13, first October 26
Median at 32°F
last March 31, first November 4
Median at 28°F
last March 18, first November 15

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 29Apr 23Apr 19Apr 16Apr 13Apr 10Apr 6Apr 3Mar 29
32°FApr 16Apr 9Apr 5Apr 2Mar 31Mar 28Mar 25Mar 19Mar 13
28°FApr 3Mar 30Mar 26Mar 23Mar 18Mar 15Mar 11Mar 6Feb 26
24°FMar 24Mar 17Mar 13Mar 9Mar 5Feb 28Feb 24Feb 17Feb 9
20°FMar 15Mar 7Mar 1Feb 23Feb 15Feb 8Feb 2Jan 28Jan 18
16°FMar 4Feb 21Feb 9Feb 2Jan 30Jan 25Jan 18Jan 12Jan 4

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 13Oct 17Oct 21Oct 23Oct 26Oct 28Oct 31Nov 3Nov 6
32°FOct 22Oct 26Oct 30Nov 1Nov 4Nov 6Nov 9Nov 12Nov 18
28°FNov 1Nov 5Nov 8Nov 12Nov 15Nov 19Nov 23Nov 28Dec 5
24°FNov 12Nov 18Nov 23Nov 27Dec 1Dec 4Dec 8Dec 14Dec 24
20°FNov 27Dec 3Dec 9Dec 14Dec 21Dec 26Jan 1Jan 7Jan 15
16°FDec 11Dec 20Dec 27Jan 1Jan 5Jan 10Jan 14Jan 20Feb 1

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°F215208204199196192187183175
32°F241233228223219215211206198
28°F269259252247242238234228221
24°F304292284278271264258251242
20°F338329319310305297290282271
16°F365359350342334329321311299

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
99% of years
16°F or colder
84% 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
3,548
Cooling degree days, base 65°F
1,395
Growing degree days, base 40°F
7,249
Growing degree days, base 45°F
5,747
Growing degree days, base 50°F
4,412
Growing degree days, base 55°F
3,240
Growing degree days, base 60°F
2,238

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January786017
February616029
March4664117
April21228283
May61116521
June5285730
July0395860
August0352817
September23184611
October19829309
November473291
December709128

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 7.5 km from Granite Falls. 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 USW00003810 (Hickory FAA AP). Public domain.