Dora climate

Dora Frost Dates and Growing Season

NOAA 1991-2020 normals for Jasper, 28.5 km from Dora, elevation 486 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Jasper. 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 30 and the first fall freeze around November 4, a growing season of about 220 days.

Median at 36°F
last April 11, first October 25
Median at 32°F
last March 30, first November 4
Median at 28°F
last March 14, first November 15

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 29Apr 22Apr 18Apr 15Apr 11Apr 7Apr 4Mar 31Mar 26
32°FApr 16Apr 10Apr 5Apr 2Mar 30Mar 27Mar 22Mar 17Mar 10
28°FApr 3Mar 28Mar 22Mar 18Mar 14Mar 11Mar 6Mar 1Feb 24
24°FMar 19Mar 13Mar 8Mar 4Feb 28Feb 26Feb 21Feb 15Feb 6
20°FMar 8Mar 1Feb 24Feb 18Feb 12Feb 6Feb 2Jan 28Jan 16
16°FFeb 28Feb 15Feb 8Feb 2Jan 30Jan 23Jan 17Jan 9Dec 31

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 14Oct 18Oct 21Oct 23Oct 25Oct 28Oct 31Nov 3Nov 6
32°FOct 22Oct 27Oct 30Nov 1Nov 4Nov 6Nov 9Nov 13Nov 19
28°FNov 1Nov 4Nov 8Nov 11Nov 15Nov 19Nov 23Nov 30Dec 4
24°FNov 8Nov 15Nov 20Nov 25Nov 30Dec 2Dec 6Dec 11Dec 23
20°FNov 20Nov 29Dec 4Dec 8Dec 14Dec 23Dec 30Jan 4Jan 13
16°FDec 4Dec 11Dec 22Dec 29Jan 2Jan 7Jan 13Jan 20Jan 31

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°F218210206202198193188183177
32°F244237230225220216210205197
28°F273264257251247242237231224
24°F306296288281275268262254248
20°F338328319312305298291281270
16°F365359348340334328321311299

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
98% of years
16°F or colder
84% 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
3,134
Cooling degree days, base 65°F
1,759
Growing degree days, base 40°F
7,987
Growing degree days, base 45°F
6,433
Growing degree days, base 50°F
5,028
Growing degree days, base 55°F
3,775
Growing degree days, base 60°F
2,683

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January735136
February565149
March3888164
April17039332
May39160586
June1331780
July0456921
August0437902
September11260699
October15458380
November4178133
December654149

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 28.5 km from Dora. 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 USC00014226 (Jasper). Public domain.