Center climate

Center Frost Dates and Growing Season

NOAA 1991-2020 normals for Center 4 Ssw, 6 km from Center, elevation 7673 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Center 4 Ssw. 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 24 and the first fall freeze around September 24, a growing season of about 120 days.

Median at 36°F
last June 9, first September 13
Median at 32°F
last May 24, first September 24
Median at 28°F
last May 8, first October 2

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 23Jun 19Jun 15Jun 12Jun 9Jun 7Jun 4Jun 2May 29
32°FJun 8Jun 3May 31May 28May 24May 21May 17May 13May 9
28°FMay 24May 18May 14May 11May 8May 6May 2Apr 30Apr 26
24°FMay 10May 6May 2Apr 30Apr 28Apr 25Apr 22Apr 19Apr 15
20°FApr 30Apr 26Apr 22Apr 18Apr 15Apr 12Apr 9Apr 6Apr 2
16°FApr 21Apr 15Apr 10Apr 7Apr 4Apr 1Mar 28Mar 23Mar 17

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 2Sep 5Sep 8Sep 10Sep 13Sep 15Sep 18Sep 21Sep 25
32°FSep 12Sep 16Sep 19Sep 22Sep 24Sep 26Sep 29Oct 1Oct 5
28°FSep 20Sep 25Sep 27Sep 30Oct 2Oct 4Oct 7Oct 10Oct 14
24°FSep 28Oct 2Oct 5Oct 8Oct 11Oct 14Oct 16Oct 19Oct 23
20°FOct 6Oct 11Oct 15Oct 17Oct 19Oct 22Oct 25Oct 28Nov 2
16°FOct 15Oct 20Oct 23Oct 26Oct 29Nov 1Nov 4Nov 7Nov 11

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°F109104100969288847973
32°F139133129125120116112107101
28°F164157153150146142138133126
24°F184178173169166162158153148
20°F204198194189185181176172166
16°F231223217212207202198192184

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
8,288
Cooling degree days, base 65°F
40
Growing degree days, base 40°F
3,221
Growing degree days, base 45°F
2,243
Growing degree days, base 50°F
1,429
Growing degree days, base 55°F
765
Growing degree days, base 60°F
285

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,46000
February1,14800
March93600
April669011
May4190103
June1765282
July6324426
August9110385
September2651200
October631022
November1,01100
December1,42000

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 6 km from Center. 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 USC00051458 (Center 4 Ssw). Public domain.