Masthope climate

Masthope Frost Dates and Growing Season

NOAA 1991-2020 normals for Hawley 1 E, 13.2 km from Masthope, elevation 890 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hawley 1 E. 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 10 and the first fall freeze around October 4, a growing season of about 146 days.

Median at 36°F
last May 23, first September 24
Median at 32°F
last May 10, first October 4
Median at 28°F
last April 29, 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°FJun 3May 31May 28May 26May 23May 20May 17May 13May 7
32°FMay 26May 21May 17May 14May 10May 8May 4Apr 30Apr 26
28°FMay 13May 8May 4Apr 30Apr 29Apr 26Apr 23Apr 20Apr 15
24°FApr 30Apr 24Apr 21Apr 18Apr 15Apr 12Apr 10Apr 7Apr 2
20°FApr 16Apr 11Apr 7Apr 4Apr 2Mar 31Mar 29Mar 24Mar 19
16°FApr 3Mar 31Mar 29Mar 26Mar 23Mar 20Mar 17Mar 13Mar 9

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 3Sep 13Sep 17Sep 21Sep 24Sep 27Sep 30Oct 2Oct 6
32°FSep 21Sep 27Oct 1Oct 2Oct 4Oct 6Oct 9Oct 13Oct 18
28°FOct 1Oct 5Oct 8Oct 12Oct 16Oct 19Oct 22Oct 27Nov 1
24°FOct 11Oct 17Oct 22Oct 25Oct 29Nov 1Nov 3Nov 7Nov 12
20°FOct 26Nov 1Nov 3Nov 6Nov 9Nov 12Nov 16Nov 20Nov 25
16°FNov 7Nov 12Nov 15Nov 18Nov 22Nov 26Nov 29Dec 2Dec 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°F143137132127124120115109101
32°F166159155151146143138134126
28°F192185179174170165161156150
24°F218211206201197192188182174
20°F243237231226222218215211204
16°F267258253248244240235230224

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
7,062
Cooling degree days, base 65°F
376
Growing degree days, base 40°F
4,201
Growing degree days, base 45°F
3,148
Growing degree days, base 50°F
2,235
Growing degree days, base 55°F
1,459
Growing degree days, base 60°F
833

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,29400
February1,12100
March98306
April607148
May29919215
June8775439
July20145590
August39103529
September17532315
October510282
November81009
December1,11801

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 13.2 km from Masthope. 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 USC00363758 (Hawley 1 E). Public domain.