Enterprise climate

Enterprise Frost Dates and Growing Season

NOAA 1991-2020 normals for Enterprise, 0.4 km from Enterprise, elevation 5320 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Enterprise. 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 21 and the first fall freeze around October 2, a growing season of about 132 days.

Median at 36°F
last June 3, first September 24
Median at 32°F
last May 21, first October 2
Median at 28°F
last May 6, first October 9

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 16Jun 11Jun 7Jun 5Jun 3May 31May 28May 23May 17
32°FJun 7Jun 2May 30May 25May 21May 17May 13May 8May 4
28°FMay 26May 18May 14May 10May 6May 3Apr 30Apr 26Apr 22
24°FMay 13May 6May 1Apr 28Apr 24Apr 20Apr 17Apr 13Apr 8
20°FMay 1Apr 22Apr 17Apr 11Apr 7Apr 3Mar 30Mar 22Mar 12
16°FApr 8Apr 1Mar 23Mar 16Mar 12Mar 8Mar 3Feb 27Feb 21

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 13Sep 17Sep 19Sep 22Sep 24Sep 26Sep 29Oct 1Oct 4
32°FSep 21Sep 24Sep 27Sep 30Oct 2Oct 4Oct 6Oct 10Oct 15
28°FSep 28Oct 1Oct 4Oct 7Oct 9Oct 12Oct 15Oct 19Oct 24
24°FOct 5Oct 9Oct 13Oct 16Oct 20Oct 22Oct 25Oct 30Nov 4
20°FOct 12Oct 18Oct 22Oct 27Oct 30Nov 2Nov 6Nov 11Nov 17
16°FOct 22Oct 30Nov 3Nov 7Nov 11Nov 15Nov 19Nov 23Nov 29

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°F13312612111611310910510095
32°F153147142138132128123117111
28°F175168163159155150145140132
24°F200192186181176172167161152
20°F235225217211204197191185177
16°F271261253246239233226216204

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
6,084
Cooling degree days, base 65°F
574
Growing degree days, base 40°F
4,692
Growing degree days, base 45°F
3,530
Growing degree days, base 50°F
2,565
Growing degree days, base 55°F
1,766
Growing degree days, base 60°F
1,102

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,07400
February88600
March73207
April543040
May2949209
June6890473
July2245708
August6188648
September11041387
October468090
November80005
December1,10200

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 0.4 km from Enterprise. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00422558 (Enterprise). Public domain.