Swartz climate

Swartz Frost Dates and Growing Season

NOAA 1991-2020 normals for Monroe Delta Cc, 9.5 km from Swartz, elevation 70 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Monroe Delta Cc. 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 9 and the first fall freeze around November 14, a growing season of about 248 days.

Median at 36°F
last March 26, first November 2
Median at 32°F
last March 9, first November 14
Median at 28°F
last February 25, first November 26

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 12Apr 5Apr 2Mar 30Mar 26Mar 21Mar 17Mar 12Mar 5
32°FMar 28Mar 22Mar 16Mar 12Mar 9Mar 5Mar 2Feb 27Feb 21
28°FMar 15Mar 8Mar 4Feb 28Feb 25Feb 21Feb 16Feb 8Jan 30
24°FMar 4Feb 26Feb 20Feb 13Feb 7Feb 1Jan 28Jan 20Jan 9
20°FFeb 22Feb 12Feb 4Jan 31Jan 26Jan 19Jan 12Jan 5Dec 27
16°FFeb 13Feb 3Jan 31Jan 24Jan 17Jan 13Jan 10Jan 3Dec 26

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 25Oct 29Oct 31Nov 2Nov 5Nov 8Nov 12Nov 18
32°FOct 31Nov 4Nov 7Nov 10Nov 14Nov 18Nov 21Nov 26Dec 1
28°FNov 7Nov 14Nov 18Nov 22Nov 26Nov 30Dec 3Dec 9Dec 24
24°FNov 20Nov 28Dec 3Dec 7Dec 17Dec 25Jan 1Jan 6Jan 16
20°FDec 7Dec 18Dec 27Jan 1Jan 4Jan 9Jan 13Jan 20Feb 1
16°FDec 21Dec 30Jan 2Jan 7Jan 10Jan 14Jan 19Jan 28Feb 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°F244237231225221216211206199
32°F274265259254248243238232225
28°F309298290282276270265258249
24°F348335327319311305297288275
20°F365365363354345337331322310
16°F365365365365365365361349334

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
97% of years
20°F or colder
74% of years
16°F or colder
37% 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
2,315
Cooling degree days, base 65°F
2,439
Growing degree days, base 40°F
9,352
Growing degree days, base 45°F
7,688
Growing degree days, base 50°F
6,150
Growing degree days, base 55°F
4,757
Growing degree days, base 60°F
3,514

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January588475
February4376105
March26428266
April9791447
May10266721
June0447897
July05601,024
August05421,007
September5352796
October87121503
November30817208
December5196100

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 9.5 km from Swartz. 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 USC00166314 (Monroe Delta Cc). Public domain.