Hampton climate

Hampton Frost Dates and Growing Season

NOAA 1991-2020 normals for Le Claire L&d 14, 2.2 km from Hampton, elevation 577 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Le Claire L&d 14. 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 16 and the first fall freeze around October 25, a growing season of about 190 days.

Median at 36°F
last April 27, first October 15
Median at 32°F
last April 16, first October 25
Median at 28°F
last April 6, first November 2

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 8May 5May 2Apr 30Apr 27Apr 23Apr 20Apr 17Apr 11
32°FApr 30Apr 25Apr 22Apr 18Apr 16Apr 13Apr 9Apr 6Apr 2
28°FApr 21Apr 15Apr 11Apr 8Apr 6Apr 3Apr 1Mar 27Mar 21
24°FApr 9Apr 5Apr 2Mar 31Mar 27Mar 23Mar 19Mar 15Mar 10
20°FApr 2Mar 29Mar 24Mar 21Mar 17Mar 14Mar 11Mar 7Mar 3
16°FMar 26Mar 20Mar 15Mar 13Mar 10Mar 7Mar 4Mar 1Feb 24

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 1Oct 6Oct 10Oct 12Oct 15Oct 18Oct 20Oct 24Oct 28
32°FOct 11Oct 16Oct 20Oct 22Oct 25Oct 28Oct 30Nov 1Nov 6
28°FOct 23Oct 27Oct 30Nov 1Nov 2Nov 5Nov 8Nov 13Nov 18
24°FNov 1Nov 4Nov 7Nov 10Nov 13Nov 16Nov 19Nov 23Nov 29
20°FNov 7Nov 12Nov 16Nov 19Nov 22Nov 26Nov 30Dec 2Dec 8
16°FNov 13Nov 18Nov 23Nov 27Dec 1Dec 2Dec 6Dec 9Dec 16

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°F190183178174171167163158151
32°F209203198194190186182178172
28°F229222218213210206202197191
24°F252244238233229225222217210
20°F272262258252248243239233226
16°F286279274269264260255249243

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
6,229
Cooling degree days, base 65°F
1,024
Growing degree days, base 40°F
5,577
Growing degree days, base 45°F
4,427
Growing degree days, base 50°F
3,395
Growing degree days, base 55°F
2,480
Growing degree days, base 60°F
1,690

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,32300
February1,08601
March845023
April4506114
May16265375
June17224657
July1328792
August4269730
September79118491
October36414184
November753026
December1,14402

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 2.2 km from Hampton. 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 USC00134705 (Le Claire L&d 14). Public domain.