Riesel climate

Riesel Frost Dates and Growing Season

NOAA 1991-2020 normals for Marlin, 19.4 km from Riesel, elevation 407 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Marlin. 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 21 and the first fall freeze around November 9, a growing season of about 234 days.

Median at 36°F
last April 3, first November 2
Median at 32°F
last March 21, first November 9
Median at 28°F
last March 8, first November 18

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 25Apr 17Apr 11Apr 6Apr 3Mar 31Mar 27Mar 21Mar 14
32°FApr 10Apr 3Mar 31Mar 26Mar 21Mar 17Mar 11Mar 7Feb 27
28°FMar 31Mar 22Mar 17Mar 12Mar 8Mar 3Feb 28Feb 23Feb 13
24°FMar 16Mar 9Mar 5Feb 28Feb 24Feb 17Feb 10Feb 1Jan 24
20°FMar 8Mar 1Feb 22Feb 12Feb 3Jan 29Jan 21Jan 10Dec 27
16°FFeb 27Feb 12Feb 2Jan 27Jan 20Jan 11Jan 4Dec 29Dec 15

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 21Oct 26Oct 29Nov 1Nov 2Nov 5Nov 7Nov 11Nov 16
32°FOct 29Nov 1Nov 4Nov 7Nov 9Nov 13Nov 16Nov 20Nov 26
28°FNov 3Nov 8Nov 11Nov 14Nov 18Nov 22Nov 27Dec 1Dec 6
24°FNov 10Nov 16Nov 22Nov 26Dec 1Dec 4Dec 9Dec 16Dec 29
20°FNov 19Nov 27Dec 2Dec 8Dec 13Dec 22Jan 1Jan 7Jan 19
16°FNov 30Dec 8Dec 20Dec 28Jan 1Jan 6Jan 12Jan 22Feb 6

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°F236229222216211208202195188
32°F259250244239234228222215208
28°F285274267261256250245237228
24°F318304295288281274267260249
20°F356342334325318309301291277
16°F365365365364354345336327308

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
94% of years
16°F or colder
63% 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
2,295
Cooling degree days, base 65°F
2,429
Growing degree days, base 40°F
9,359
Growing degree days, base 45°F
7,691
Growing degree days, base 50°F
6,146
Growing degree days, base 55°F
4,746
Growing degree days, base 60°F
3,507

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January582267
February4217111
March27423253
April10085440
May15238688
June0434883
July05551,020
August05611,026
September3362808
October67137537
November29921223
December534488

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 19.4 km from Riesel. 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 USC00415611 (Marlin). Public domain.