Hazelton climate

Hazelton Frost Dates and Growing Season

NOAA 1991-2020 normals for Hazelton, 0.2 km from Hazelton, elevation 4060 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hazelton. 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 5, a growing season of about 149 days.

Median at 36°F
last May 25, first September 22
Median at 32°F
last May 7, first October 5
Median at 28°F
last April 23, first October 17

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 28May 25May 20May 17May 12May 7
32°FMay 26May 17May 13May 10May 7May 4May 2Apr 29Apr 24
28°FMay 8May 3Apr 30Apr 27Apr 23Apr 20Apr 16Apr 11Apr 6
24°FApr 25Apr 17Apr 13Apr 7Apr 4Mar 31Mar 26Mar 17Mar 10
20°FApr 4Mar 28Mar 18Mar 12Mar 9Mar 6Mar 3Feb 27Feb 19
16°FMar 10Mar 5Mar 3Feb 28Feb 25Feb 21Feb 17Feb 12Feb 6

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 6Sep 12Sep 15Sep 19Sep 22Sep 25Sep 28Oct 1Oct 6
32°FSep 19Sep 25Sep 29Oct 1Oct 5Oct 7Oct 10Oct 14Oct 19
28°FOct 2Oct 7Oct 11Oct 14Oct 17Oct 20Oct 23Oct 27Nov 1
24°FOct 14Oct 19Oct 22Oct 25Oct 28Oct 31Nov 3Nov 8Nov 13
20°FOct 21Oct 27Nov 1Nov 4Nov 7Nov 11Nov 15Nov 20Nov 24
16°FOct 29Nov 6Nov 11Nov 15Nov 18Nov 22Nov 25Nov 29Dec 7

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°F14013312712411911510910395
32°F169162158153149145140134126
28°F200192186182176173167162154
24°F236226219213208202196191183
20°F267259252246242235230222211
16°F293284277271266261256249239

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
6,502
Cooling degree days, base 65°F
562
Growing degree days, base 40°F
4,457
Growing degree days, base 45°F
3,352
Growing degree days, base 50°F
2,428
Growing degree days, base 55°F
1,667
Growing degree days, base 60°F
1,045

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,15300
February92700
March75306
April560041
May30712203
June10667413
July10247702
August17196643
September15440343
October514174
November85503
December1,14700

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 0.2 km from Hazelton. 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 USC00104140 (Hazelton). Public domain.