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USDA Hardiness Zone 6b

Frost Dates for 06450 — Meriden, Connecticut

NOAA 1991–2020 normals from Meriden Markham Municipal Airport, CT (103 ft), 3 miles southwest.

Updated

In Meriden, the last spring frost (32°F) is around April 26 in half of years and has passed by May 9 in nine years out of ten. The first fall frost comes around October 16, as early as October 4 one year in ten, leaving a typical freeze-free season of 175 days (NOAA, Meriden Markham Municipal Airport, CT).

Last spring frost
April 26

50% probability

First fall frost
October 16

50% probability

Growing season
175 days

freeze-free, 50%

Hardiness zone
6b

-5 to 0°F (-20.6 to -17.8°C) coldest night

First snow
December 9

median, 1991–2020

Last snow
March 21

median, 1991–2020

Winters with snow
100%

18 of 18 observed

Snow per year
—

NOAA normal

Frost risk by date in Meriden

Half of springs at Meriden Markham Municipal Airport, CT see their last 32°F night by April 26; only one in ten is past it by April 11, and one in ten still has one after May 9. Planting tender crops after May 1 leaves a 30% risk of a frost on them, after May 5 20%, and after May 9 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 86% of the 28 Connecticut stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 16 in half of years, as early as October 4 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 14 days later, around October 30; in spring the one-in-ten date for 28°F is April 28, 11 days before the 32°F one. The freeze-free season lasts 175 days in a typical year, shorter than at 54% of the 28 Connecticut stations; it reaches 194 days one year in ten and falls short of 156 one year in ten. On average 129 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 11 days longer, to about May 7, and return around October 6. Severe cold of 16°F or below comes every winter, usually between December 3 and March 9.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°FApr 24Apr 29May 2May 4May 7May 10May 12May 17May 21
32°FApr 11Apr 17Apr 20Apr 23Apr 26Apr 29May 1May 5May 9
28°FMar 30Apr 2Apr 5Apr 7Apr 10Apr 13Apr 17Apr 21Apr 28
24°FMar 13Mar 19Mar 24Mar 27Mar 30Mar 31Apr 3Apr 5Apr 12
20°FMar 3Mar 8Mar 11Mar 15Mar 18Mar 21Mar 24Mar 27Mar 31
16°FFeb 20Feb 27Mar 2Mar 6Mar 9Mar 12Mar 15Mar 19Mar 24
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°FSep 26Sep 30Oct 1Oct 4Oct 6Oct 8Oct 11Oct 14Oct 19
32°FOct 4Oct 8Oct 11Oct 14Oct 16Oct 20Oct 23Oct 28Nov 1
28°FOct 14Oct 19Oct 23Oct 26Oct 30Nov 1Nov 4Nov 8Nov 12
24°FOct 25Oct 31Nov 2Nov 5Nov 9Nov 12Nov 15Nov 19Nov 25
20°FNov 6Nov 11Nov 15Nov 18Nov 22Nov 25Nov 29Dec 2Dec 6
16°FNov 19Nov 24Nov 28Dec 1Dec 3Dec 7Dec 11Dec 16Dec 22

Freeze probabilities 1991–2020 at Meriden Markham Municipal Airport, CT, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.

Frost risk on any date in 06450 →Compare Meriden with another place →

Weather by month in Meriden

July is the warmest month at Meriden Markham Municipal Airport, CT, averaging 84°F by day and 63°F at night; January is the coldest at 37°F and 19°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 33% of years.

Warmth for growing adds up to 2,927 growing degree days a year (base 50°F), more than at 57% of the 28 Connecticut stations. 31% of them (921) have built up by the end of June, and July adds the most, 721. Precipitation totals 45.0 inches a year, most in October (4.5") and least in February (2.9"); May to September bring 42% of it.

Monthly normals 1991–2020 at Meriden Markham Municipal Airport, CT
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan37193.1100%281
Feb39202.9100%251
Mar48284.1100%2111
Apr60384.199%882
May70483.533%1291
Jun79574.10%0536
Jul84633.40%0721
Aug82613.50%0674
Sep75544.32%0436
Oct64424.586%5148
Nov52323.4100%1624
Dec42254.1100%263

Monthly normals 1991–2020 at Meriden Markham Municipal Airport, CT (103 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.

Compared with the next station

The nearest other station, Mt Carmel, CT, 11 miles southwest of Meriden, has a last frost 8 days earlier (April 18), a first frost 10 days later (October 26), a season 16 days longer.

Frost dates for 06770 (Naugatuck) →

When it snows in Meriden, Connecticut

The first measurable snow (0.1 inch or more) in Meriden usually arrives around December 9, and the last of the season around March 21. Those are the middle dates across the winters of 1991–2020 at Shuttle Meadow Rsvr, CT, 8 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 36 days after the last snow.

Planting calendar for 06450

What to do and when, from the 50% frost dates for Meriden, Connecticut
WhenWhat to do
February 15 – March 1Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
March 1 – March 15Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 29 – April 12Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 26 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by July 24Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 2Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 16 onwardPlant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter.

The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.

Where these figures come from

ZIP 06450 is 3 miles from Meriden Markham Municipal Airport, CT, which stands at 103 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 21 other ZIP codes share the station; its figures are presented in full for 06457 (Middletown). The 2023 USDA Plant Hardiness Zone Map lists ZIP 06450 in zone 6b, the band where the coldest night of the year averaged -5 to 0°F (-20.6 to -17.8°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Connecticut →

Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.

Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.

ZIP codes measured at the same station

Other zone 6b places in Connecticut