Scottsville climate

Scottsville Frost Dates and Growing Season

NOAA 1991-2020 normals for Palmyra 3S, 20.4 km from Scottsville, elevation 410 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Palmyra 3S. 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 23 and the first fall freeze around October 21, a growing season of about 180 days.

Median at 36°F
last May 3, first October 12
Median at 32°F
last April 23, first October 21
Median at 28°F
last April 9, first October 31

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

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 30Oct 4Oct 7Oct 9Oct 12Oct 14Oct 17Oct 20Oct 24
32°FOct 8Oct 12Oct 15Oct 18Oct 21Oct 24Oct 26Oct 29Nov 1
28°FOct 15Oct 21Oct 25Oct 28Oct 31Nov 1Nov 4Nov 7Nov 12
24°FOct 27Nov 1Nov 3Nov 6Nov 9Nov 11Nov 15Nov 19Nov 28
20°FNov 6Nov 11Nov 14Nov 18Nov 22Nov 27Dec 1Dec 6Dec 14
16°FNov 16Nov 22Nov 29Dec 3Dec 7Dec 12Dec 19Dec 26Jan 5

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°F179173168164161157153147140
32°F200194188185180176172167160
28°F223216210206202198194188180
24°F252244237231226222217212205
20°F280268262256250246242235227
16°F308301293285279273267260252

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
4,571
Cooling degree days, base 65°F
1,066
Growing degree days, base 40°F
6,234
Growing degree days, base 45°F
4,887
Growing degree days, base 50°F
3,701
Growing degree days, base 55°F
2,668
Growing degree days, base 60°F
1,791

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January929013
February772014
March639259
April33117190
May12769411
June14209645
July0334798
August2290753
September52126524
October29517220
November580156
December831018

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 20.4 km from Scottsville. 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 USC00446491 (Palmyra 3S). Public domain.