Payson climate

Payson Frost Dates and Growing Season

NOAA 1991-2020 normals for Santaquin Chlorinator, 10.4 km from Payson, elevation 5160 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Santaquin Chlorinator. 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 4 and the first fall freeze around October 11, a growing season of about 157 days.

Median at 36°F
last May 23, first October 1
Median at 32°F
last May 4, first October 11
Median at 28°F
last April 19, first October 23

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 8Jun 4May 31May 27May 23May 18May 14May 9May 3
32°FMay 28May 19May 14May 8May 4May 1Apr 28Apr 24Apr 18
28°FMay 10May 1Apr 26Apr 22Apr 19Apr 15Apr 11Apr 7Mar 31
24°FApr 20Apr 14Apr 9Apr 5Apr 1Mar 29Mar 25Mar 18Mar 11
20°FApr 4Mar 28Mar 21Mar 15Mar 11Mar 7Mar 4Feb 28Feb 23
16°FMar 14Mar 7Mar 3Feb 28Feb 26Feb 21Feb 18Feb 12Feb 5

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 18Sep 23Sep 26Sep 29Oct 1Oct 3Oct 6Oct 9Oct 15
32°FSep 27Oct 1Oct 5Oct 8Oct 11Oct 14Oct 17Oct 21Oct 26
28°FOct 8Oct 12Oct 16Oct 20Oct 23Oct 27Oct 30Nov 3Nov 7
24°FOct 19Oct 24Oct 28Nov 1Nov 3Nov 7Nov 10Nov 13Nov 19
20°FOct 28Nov 2Nov 6Nov 9Nov 13Nov 17Nov 20Nov 23Nov 27
16°FNov 4Nov 10Nov 16Nov 19Nov 22Nov 25Nov 28Dec 1Dec 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°F154147141136131127122117109
32°F179171166162157153147140132
28°F209202195190185180174168160
24°F239232226220215210204197189
20°F268259254247242237231224213
16°F293284278273268263258251241

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
6,093
Cooling degree days, base 65°F
915
Growing degree days, base 40°F
5,151
Growing degree days, base 45°F
4,001
Growing degree days, base 50°F
3,017
Growing degree days, base 55°F
2,184
Growing degree days, base 60°F
1,485

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,12800
February89502
March724022
April522273
May27824245
June76141518
July5354814
August6301759
September10690441
October4374129
November795015
December1,12000

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 10.4 km from Payson. 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 USC00427686 (Santaquin Chlorinator). Public domain.