Newport climate

Newport Frost Dates and Growing Season

NOAA 1991-2020 normals for Newport Rose, 3.3 km from Newport, elevation 15 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Newport Rose. 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 7 and the first fall freeze around November 13, a growing season of about 216 days.

Median at 36°F
last April 23, first November 1
Median at 32°F
last April 7, first November 13
Median at 28°F
last March 28, first November 25

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 6May 2Apr 29Apr 26Apr 23Apr 21Apr 19Apr 15Apr 10
32°FApr 21Apr 17Apr 14Apr 10Apr 7Apr 5Apr 3Apr 1Mar 28
28°FApr 8Apr 4Apr 1Mar 31Mar 28Mar 25Mar 22Mar 18Mar 14
24°FMar 31Mar 27Mar 23Mar 19Mar 17Mar 14Mar 11Mar 7Mar 3
20°FMar 23Mar 18Mar 14Mar 11Mar 8Mar 5Mar 3Feb 27Feb 20
16°FMar 14Mar 8Mar 5Mar 2Feb 28Feb 23Feb 18Feb 12Feb 4

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 17Oct 22Oct 27Oct 30Nov 1Nov 3Nov 5Nov 8Nov 12
32°FOct 31Nov 4Nov 7Nov 10Nov 13Nov 15Nov 18Nov 21Nov 27
28°FNov 11Nov 15Nov 19Nov 22Nov 25Nov 28Dec 1Dec 5Dec 11
24°FNov 21Nov 27Dec 1Dec 3Dec 6Dec 10Dec 14Dec 19Dec 24
20°FDec 1Dec 6Dec 10Dec 15Dec 18Dec 22Dec 26Dec 31Jan 7
16°FDec 11Dec 17Dec 22Dec 26Dec 30Jan 2Jan 5Jan 12Jan 18

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°F207201197192189186181176167
32°F235230224220216212208202194
28°F263255249245242237234227219
24°F286279273269264259255248242
20°F305298294289284280274269261
16°F326317311306303298294289281

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
5,369
Cooling degree days, base 65°F
518
Growing degree days, base 40°F
5,047
Growing degree days, base 45°F
3,789
Growing degree days, base 50°F
2,713
Growing degree days, base 55°F
1,813
Growing degree days, base 60°F
1,083

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,04600
February90900
March81202
April527032
May2636213
June6454439
July3184646
August2190652
September4880482
October2886203
November563040
December84504

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 3.3 km from Newport. 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 USC00375215 (Newport Rose). Public domain.