Dublin climate

Dublin Frost Dates and Growing Season

NOAA 1991-2020 normals for Dublin 2SE, 4.3 km from Dublin, elevation 1468 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Dublin 2SE. 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 16 and the first fall freeze around November 16, a growing season of about 243 days.

Median at 36°F
last March 31, first November 6
Median at 32°F
last March 16, first November 16
Median at 28°F
last March 3, first November 29

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 18Apr 11Apr 6Apr 3Mar 31Mar 27Mar 23Mar 17Mar 8
32°FApr 5Mar 31Mar 26Mar 21Mar 16Mar 12Mar 7Mar 4Feb 26
28°FMar 24Mar 16Mar 11Mar 7Mar 3Feb 28Feb 25Feb 18Feb 11
24°FMar 11Mar 5Mar 1Feb 25Feb 18Feb 12Feb 7Jan 31Jan 23
20°FMar 4Feb 24Feb 15Feb 8Feb 2Jan 29Jan 23Jan 13Jan 1
16°FFeb 16Feb 8Jan 31Jan 27Jan 20Jan 13Jan 8Jan 2Dec 21

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 23Oct 29Nov 1Nov 4Nov 6Nov 9Nov 13Nov 17Nov 23
32°FNov 1Nov 5Nov 9Nov 12Nov 16Nov 20Nov 24Nov 28Dec 3
28°FNov 9Nov 15Nov 20Nov 26Nov 29Dec 1Dec 5Dec 10Dec 17
24°FNov 19Nov 28Dec 1Dec 6Dec 10Dec 16Dec 21Dec 27Jan 3
20°FDec 1Dec 9Dec 17Dec 23Dec 28Jan 2Jan 7Jan 15Jan 29
16°FDec 10Dec 18Dec 26Jan 1Jan 5Jan 10Jan 16Jan 26Feb 5

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°F245237230225221216211205197
32°F271262255249243238233226217
28°F298290283276270265259252243
24°F332322314307299294286277269
20°F365354344336330325317307297
16°F365365365365357348339333322

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
99% of years
20°F or colder
89% of years
16°F or colder
55% 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
2,627
Cooling degree days, base 65°F
2,207
Growing degree days, base 40°F
8,882
Growing degree days, base 45°F
7,261
Growing degree days, base 50°F
5,769
Growing degree days, base 55°F
4,422
Growing degree days, base 60°F
3,234

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January653153
February476489
March30720232
April12568401
May20220665
June1394843
July05391,004
August05361,001
September9309750
October95104480
November33912190
December603161

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 Dublin. 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 USC00412598 (Dublin 2SE). Public domain.