Newport climate

Newport Frost Dates and Growing Season

NOAA 1991-2020 normals for Newport, 0.7 km from Newport, elevation 676 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Newport. 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 26, a growing season of about 185 days.

Median at 36°F
last May 3, first October 17
Median at 32°F
last April 23, first October 26
Median at 28°F
last April 10, first November 3

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 20May 13May 9May 6May 3Apr 30Apr 28Apr 24Apr 20
32°FMay 10May 4Apr 30Apr 26Apr 23Apr 20Apr 17Apr 15Apr 10
28°FApr 25Apr 20Apr 16Apr 14Apr 10Apr 7Apr 4Apr 1Mar 28
24°FApr 13Apr 8Apr 5Apr 2Mar 31Mar 28Mar 25Mar 20Mar 14
20°FApr 3Mar 31Mar 27Mar 22Mar 19Mar 16Mar 12Mar 7Feb 28
16°FMar 25Mar 19Mar 15Mar 11Mar 7Mar 3Feb 27Feb 21Feb 12

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 4Oct 7Oct 11Oct 14Oct 17Oct 19Oct 22Oct 24Oct 28
32°FOct 12Oct 18Oct 21Oct 24Oct 26Oct 28Oct 31Nov 2Nov 6
28°FOct 24Oct 29Oct 31Nov 1Nov 3Nov 5Nov 8Nov 11Nov 16
24°FNov 1Nov 5Nov 7Nov 10Nov 12Nov 15Nov 19Nov 23Nov 29
20°FNov 8Nov 13Nov 17Nov 21Nov 24Nov 29Dec 2Dec 8Dec 16
16°FNov 19Nov 26Dec 1Dec 5Dec 10Dec 15Dec 20Dec 25Jan 1

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°F184178173170165161157152145
32°F204197192188185181176171164
28°F226220215211207203199195189
24°F252242236232228225221216209
20°F278268262257252248242237230
16°F305296289284279274268261253

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
5,218
Cooling degree days, base 65°F
902
Growing degree days, base 40°F
5,788
Growing degree days, base 45°F
4,524
Growing degree days, base 50°F
3,408
Growing degree days, base 55°F
2,431
Growing degree days, base 60°F
1,595

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,06907
February89208
March736141
April38011163
May15161382
June22178606
July1280744
August3248710
September63108496
October32815199
November650042
December924011

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 0.7 km from Newport. 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 USC00335939 (Newport). Public domain.