Wright City climate

Wright City Frost Dates and Growing Season

NOAA 1991-2020 normals for Warrenton 1 N, 10.3 km from Wright City, elevation 827 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Warrenton 1 N. 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 April 14 and the first fall freeze around October 23, a growing season of about 191 days.

Median at 36°F
last April 28, first October 14
Median at 32°F
last April 14, first October 23
Median at 28°F
last April 3, first November 2

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

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 29Oct 4Oct 8Oct 11Oct 14Oct 16Oct 19Oct 21Oct 25
32°FOct 9Oct 15Oct 18Oct 21Oct 23Oct 26Oct 29Nov 1Nov 5
28°FOct 20Oct 25Oct 28Oct 31Nov 2Nov 5Nov 8Nov 12Nov 18
24°FOct 31Nov 3Nov 7Nov 10Nov 14Nov 17Nov 21Nov 26Dec 2
20°FNov 6Nov 11Nov 16Nov 21Nov 24Nov 28Dec 1Dec 5Dec 13
16°FNov 15Nov 22Nov 26Dec 1Dec 4Dec 8Dec 13Dec 18Dec 24

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°F189182176173169164160154147
32°F212205200196191187182176169
28°F236228222218213209205200193
24°F262252246241236232227221214
20°F281271265261256251247240231
16°F301293286280275269264257249

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
5,041
Cooling degree days, base 65°F
1,254
Growing degree days, base 40°F
6,354
Growing degree days, base 45°F
5,065
Growing degree days, base 50°F
3,915
Growing degree days, base 55°F
2,895
Growing degree days, base 60°F
2,003

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,10805
February877013
March658471
April32522209
May11988439
June11258697
July1376840
August2328790
September61148539
October29627241
November623262
December95908

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 10.3 km from Wright City. 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 USC00238725 (Warrenton 1 N). Public domain.