Prosper climate

Prosper Frost Dates and Growing Season

NOAA 1991-2020 normals for Mckinney Muni AP, 20.6 km from Prosper, elevation 580 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Mckinney Muni AP. 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 March 18 and the first fall freeze around November 11, a growing season of about 239 days.

Median at 36°F
last April 3, first November 1
Median at 32°F
last March 18, first November 11
Median at 28°F
last March 4, first November 24

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°FApr 22Apr 16Apr 11Apr 6Apr 3Mar 31Mar 27Mar 21Mar 14
32°FApr 7Apr 2Mar 27Mar 22Mar 18Mar 13Mar 10Mar 6Feb 28
28°FMar 22Mar 16Mar 11Mar 8Mar 4Feb 28Feb 24Feb 19Feb 9
24°FMar 10Mar 5Feb 28Feb 23Feb 17Feb 10Feb 3Jan 29Jan 19
20°FMar 1Feb 19Feb 10Feb 3Jan 29Jan 23Jan 17Jan 7Dec 30
16°FFeb 14Feb 5Jan 29Jan 22Jan 17Jan 12Jan 4Dec 30Dec 21

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°FOct 19Oct 23Oct 27Oct 30Nov 1Nov 4Nov 7Nov 11Nov 18
32°FOct 27Nov 1Nov 5Nov 8Nov 11Nov 16Nov 20Nov 24Dec 1
28°FNov 6Nov 11Nov 16Nov 20Nov 24Nov 28Dec 2Dec 7Dec 14
24°FNov 17Nov 24Nov 29Dec 3Dec 8Dec 14Dec 20Dec 28Jan 4
20°FNov 30Dec 6Dec 13Dec 20Dec 26Jan 1Jan 4Jan 13Jan 25
16°FDec 11Dec 19Dec 25Dec 31Jan 4Jan 9Jan 16Jan 22Feb 3

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°F239229223218213208204198190
32°F266257250244239233227221211
28°F294283276271266259254247237
24°F330319309301295288282274262
20°F365353344337331323315304293
16°F365365365365358350342333320

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
99% of years
20°F or colder
89% of years
16°F or colder
55% 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
2,498
Cooling degree days, base 65°F
2,531
Growing degree days, base 40°F
9,297
Growing degree days, base 45°F
7,655
Growing degree days, base 50°F
6,146
Growing degree days, base 55°F
4,788
Growing degree days, base 60°F
3,579

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January631255
February457699
March28925242
April11277421
May15251701
June0463913
July06011,066
August05981,063
September5362807
October90123501
November32120206
December579473

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 20.6 km from Prosper. 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 USW00053914 (Mckinney Muni AP). Public domain.