Rome climate

Rome Frost Dates and Growing Season

NOAA 1991-2020 normals for Rome Griffiss Airfield, 4.3 km from Rome, elevation 519 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Rome Griffiss Airfield. 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 May 6 and the first fall freeze around October 13, a growing season of about 157 days.

Median at 36°F
last May 17, first October 1
Median at 32°F
last May 6, first October 13
Median at 28°F
last April 26, first October 27

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°FJun 1May 28May 24May 20May 17May 14May 11May 7Apr 30
32°FMay 20May 15May 11May 8May 6May 3Apr 30Apr 27Apr 22
28°FMay 10May 5May 2Apr 29Apr 26Apr 22Apr 20Apr 17Apr 12
24°FMay 1Apr 23Apr 20Apr 17Apr 13Apr 10Apr 7Apr 4Apr 1
20°FApr 16Apr 11Apr 8Apr 5Apr 3Apr 1Mar 31Mar 27Mar 21
16°FApr 7Apr 3Apr 1Mar 30Mar 28Mar 24Mar 21Mar 17Mar 13

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 19Sep 23Sep 26Sep 28Oct 1Oct 3Oct 5Oct 8Oct 14
32°FSep 29Oct 3Oct 6Oct 9Oct 13Oct 16Oct 19Oct 23Oct 30
28°FOct 11Oct 16Oct 20Oct 24Oct 27Oct 31Nov 3Nov 6Nov 12
24°FOct 24Oct 30Nov 2Nov 5Nov 9Nov 12Nov 15Nov 19Nov 24
20°FNov 5Nov 11Nov 14Nov 17Nov 20Nov 23Nov 27Dec 1Dec 5
16°FNov 15Nov 20Nov 23Nov 27Nov 30Dec 1Dec 4Dec 7Dec 13

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°F155147142138134130126122116
32°F179171166162157153149144137
28°F204195191186182178173167159
24°F229222217213209204199194186
20°F250244240235232228223218212
16°F266259255251247244239235229

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
7,124
Cooling degree days, base 65°F
473
Growing degree days, base 40°F
4,409
Growing degree days, base 45°F
3,351
Growing degree days, base 50°F
2,432
Growing degree days, base 55°F
1,641
Growing degree days, base 60°F
976

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,34800
February1,19000
March1,03109
April617252
May27824243
June7181461
July13174626
August23138580
September15851347
October477397
November780016
December1,13801

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 4.3 km from Rome. 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 USW00064775 (Rome Griffiss Airfield). Public domain.