Pine Ridge climate

Pine Ridge Frost Dates and Growing Season

NOAA 1991-2020 normals for Pine Ridge AP, 3.1 km from Pine Ridge, elevation 3278 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Pine Ridge 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 May 16 and the first fall freeze around September 27, a growing season of about 132 days.

Median at 36°F
last May 26, first September 17
Median at 32°F
last May 16, first September 27
Median at 28°F
last May 5, first October 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°FJun 12Jun 4Jun 1May 29May 26May 23May 20May 17May 13
32°FMay 31May 26May 22May 19May 16May 14May 11May 7May 3
28°FMay 19May 15May 12May 8May 5May 2Apr 30Apr 26Apr 21
24°FMay 9May 5May 2Apr 29Apr 26Apr 22Apr 19Apr 14Apr 9
20°FMay 1Apr 25Apr 21Apr 16Apr 13Apr 9Apr 5Apr 1Mar 25
16°FApr 22Apr 15Apr 10Apr 5Apr 2Mar 30Mar 25Mar 20Mar 13

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 3Sep 7Sep 11Sep 14Sep 17Sep 21Sep 23Sep 26Sep 30
32°FSep 13Sep 18Sep 22Sep 24Sep 27Sep 30Oct 1Oct 4Oct 8
28°FSep 22Sep 27Sep 30Oct 2Oct 4Oct 6Oct 10Oct 14Oct 19
24°FSep 30Oct 4Oct 7Oct 11Oct 14Oct 17Oct 20Oct 23Oct 27
20°FOct 9Oct 13Oct 16Oct 20Oct 22Oct 25Oct 27Oct 31Nov 4
16°FOct 16Oct 20Oct 24Oct 27Oct 30Nov 1Nov 4Nov 8Nov 13

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°F1321251201161111071039891
32°F151145141136132128123117110
28°F172166160157153149145140132
24°F195187181176172168163158150
20°F215208202197193188183177169
16°F235226220215211206200194187

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
7,012
Cooling degree days, base 65°F
784
Growing degree days, base 40°F
4,748
Growing degree days, base 45°F
3,677
Growing degree days, base 50°F
2,748
Growing degree days, base 55°F
1,964
Growing degree days, base 60°F
1,309

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,26600
February1,05701
March856019
April575161
May30921223
June74125502
July7300758
August22250693
September15583390
October544594
November91508
December1,23000

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 3.1 km from Pine Ridge. 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 USW00094039 (Pine Ridge AP). Public domain.