Millville climate

Millville Frost Dates and Growing Season

NOAA 1991-2020 normals for Redding Muni AP, 11 km from Millville, elevation 497 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Redding Muni AP. 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 3 and the first fall freeze around November 21, a growing season of about 261 days.

Median at 36°F
last April 7, first November 9
Median at 32°F
last March 3, first November 21
Median at 28°F
last January 27, first December 7

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

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 28Nov 1Nov 4Nov 6Nov 9Nov 12Nov 14Nov 18Nov 22
32°FNov 7Nov 11Nov 16Nov 19Nov 21Nov 24Nov 28Dec 1Dec 7
28°FNov 20Nov 26Dec 1Dec 4Dec 7Dec 12Dec 16Dec 24Jan 5
24°FNov 30Dec 3Dec 9Dec 14Dec 18Dec 25Jan 1Jan 7Jan 22
20°FDec 1Dec 7Dec 11Dec 15Dec 24Dec 31Jan 5Jan 11Jan 22
16°F–––––––––

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°F245234227221215210206200191
32°F299283275267261254246235223
28°F356340332324316308301292277
24°F365365365365362354346338329
20°F365365365365365365365365355
16°F365365365365365365365365365

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
95% of years
24°F or colder
52% of years
20°F or colder
13% of years
16°F or colder
2% 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
2,576
Cooling degree days, base 65°F
2,032
Growing degree days, base 40°F
8,598
Growing degree days, base 45°F
6,862
Growing degree days, base 50°F
5,311
Growing degree days, base 55°F
4,006
Growing degree days, base 60°F
2,926

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January544035
February405175
March3314165
April19527288
May60158563
June7372815
July05721,037
August0496961
September5313758
October9387460
November3642129
December570027

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 11 km from Millville. 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 USW00024257 (Redding Muni AP). Public domain.