Julesburg climate

Julesburg Frost Dates and Growing Season

NOAA 1991-2020 normals for Julesburg, 0.1 km from Julesburg, elevation 3477 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Julesburg. 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 7 and the first fall freeze around October 6, a growing season of about 152 days.

Median at 36°F
last May 16, first September 28
Median at 32°F
last May 7, first October 6
Median at 28°F
last April 27, first October 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°FMay 29May 24May 20May 18May 16May 14May 11May 8May 5
32°FMay 18May 14May 12May 9May 7May 4May 1Apr 29Apr 23
28°FMay 9May 5May 3Apr 30Apr 27Apr 24Apr 20Apr 17Apr 12
24°FMay 1Apr 26Apr 22Apr 19Apr 15Apr 12Apr 8Apr 3Mar 30
20°FApr 21Apr 14Apr 9Apr 5Apr 2Mar 30Mar 26Mar 21Mar 15
16°FApr 9Apr 3Mar 30Mar 26Mar 22Mar 17Mar 13Mar 9Mar 3

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 14Sep 20Sep 23Sep 25Sep 28Oct 1Oct 3Oct 5Oct 8
32°FSep 23Sep 27Oct 1Oct 4Oct 6Oct 8Oct 11Oct 14Oct 17
28°FOct 2Oct 7Oct 10Oct 13Oct 15Oct 17Oct 19Oct 22Oct 26
24°FOct 9Oct 14Oct 17Oct 20Oct 23Oct 25Oct 27Oct 31Nov 4
20°FOct 16Oct 21Oct 25Oct 28Oct 31Nov 2Nov 5Nov 9Nov 15
16°FOct 24Oct 30Nov 2Nov 5Nov 8Nov 12Nov 15Nov 19Nov 24

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°F150145142139134131126122115
32°F170164159155152149145140133
28°F189183177174170167163158151
24°F210204199194190186181176170
20°F232225219215211207202197189
16°F254246241236231225220214206

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
6,230
Cooling degree days, base 65°F
784
Growing degree days, base 40°F
5,049
Growing degree days, base 45°F
3,901
Growing degree days, base 50°F
2,910
Growing degree days, base 55°F
2,064
Growing degree days, base 60°F
1,356

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,14100
February94901
March769020
April504282
May25428270
June46148553
July4296758
August12232685
September11875414
October4724117
November822011
December1,13900

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 0.1 km from Julesburg. 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 USC00054413 (Julesburg). Public domain.