Dacono climate

Dacono Frost Dates and Growing Season

NOAA 1991-2020 normals for Brighton 3 Se, 18 km from Dacono, elevation 5016 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Brighton 3 Se. 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 3 and the first fall freeze around October 7, a growing season of about 155 days.

Median at 36°F
last May 13, first September 30
Median at 32°F
last May 3, first October 7
Median at 28°F
last April 23, first October 16

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 27May 21May 18May 16May 13May 11May 9May 6May 3
32°FMay 16May 12May 8May 6May 3May 1Apr 30Apr 27Apr 22
28°FMay 7May 2Apr 30Apr 27Apr 23Apr 20Apr 17Apr 14Apr 8
24°FApr 28Apr 22Apr 17Apr 13Apr 9Apr 6Apr 3Mar 31Mar 24
20°FApr 15Apr 8Apr 4Apr 1Mar 29Mar 25Mar 20Mar 16Mar 10
16°FApr 5Mar 31Mar 25Mar 20Mar 16Mar 12Mar 8Mar 3Feb 26

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 17Sep 22Sep 25Sep 28Sep 30Oct 2Oct 4Oct 7Oct 10
32°FSep 26Sep 30Oct 2Oct 5Oct 7Oct 10Oct 13Oct 16Oct 19
28°FOct 4Oct 7Oct 11Oct 14Oct 16Oct 19Oct 22Oct 25Oct 29
24°FOct 13Oct 17Oct 21Oct 23Oct 26Oct 29Nov 1Nov 4Nov 10
20°FOct 20Oct 25Oct 29Nov 1Nov 4Nov 7Nov 10Nov 14Nov 18
16°FOct 27Nov 2Nov 5Nov 9Nov 13Nov 16Nov 20Nov 23Nov 27

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°F152147143140137133130126119
32°F172166162158155152148144138
28°F193187182178174169166162155
24°F217211206201197194189184176
20°F241234228223219214209203195
16°F263254249243238232226220212

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
5,964
Cooling degree days, base 65°F
753
Growing degree days, base 40°F
5,133
Growing degree days, base 45°F
3,944
Growing degree days, base 50°F
2,923
Growing degree days, base 55°F
2,058
Growing degree days, base 60°F
1,334

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,07701
February91803
March735026
April499186
May25322269
June45142548
July5287747
August9226682
September11472417
October4532124
November776020
December1,08001

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 18 km from Dacono. 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 USC00050950 (Brighton 3 Se). Public domain.