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USDA Hardiness Zone 8b

Frost Dates for 39648 — Mccomb, Mississippi

NOAA 1991–2020 normals from Mccomb/Pike Co/John E Lewis Airport, MS (413 ft), 4 miles southwest.

Updated

In Mccomb, the last spring frost (32°F) is around March 11 in half of years and has passed by April 2 in nine years out of ten. The first fall frost comes around November 18, as early as November 1 one year in ten, leaving a typical freeze-free season of 253 days (NOAA, Mccomb/Pike Co/John E Lewis Airport, MS).

Last spring frost
March 11

50% probability

First fall frost
November 18

50% probability

Growing season
253 days

freeze-free, 50%

Hardiness zone
8b

15 to 20°F (-9.4 to -6.7°C) coldest night

First snow
Rare

median, 1991–2020

Last snow
Rare

median, 1991–2020

Winters with snow
25%

4 of 16 observed

Snow per year
0.2"

NOAA normal

Frost risk by date in Mccomb

Half of springs at Mccomb/Pike Co/John E Lewis Airport, MS see their last 32°F night by March 11; only one in ten is past it by February 17, and one in ten still has one after April 2. Planting tender crops after March 20 leaves a 30% risk of a frost on them, after March 26 20%, and after April 2 10%. The 22 days between the even-odds date and the one-in-ten date is wider than at 85% of the 96 Mississippi stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.

In fall the first 32°F night comes by November 18 in half of years, as early as November 1 one year in ten, and holds off past December 7 one year in ten. A hard freeze of 28°F follows 13 days later, around December 1; in spring the one-in-ten date for 28°F is March 18, 15 days before the 32°F one. The freeze-free season lasts 253 days in a typical year, longer than at 80% of the 96 Mississippi stations; it reaches 282 days one year in ten and falls short of 225 one year in ten. On average 30 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 17 days longer, to about March 28, and return around November 7. Nights of 24°F, cold enough to damage hardier plants, come in 93% of winters and 16°F in 27%.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°FMar 8Mar 14Mar 19Mar 24Mar 28Apr 1Apr 5Apr 9Apr 17
32°FFeb 17Feb 25Mar 2Mar 8Mar 11Mar 15Mar 20Mar 26Apr 2
28°FJan 27Feb 5Feb 13Feb 19Feb 25Mar 1Mar 6Mar 11Mar 18
24°F93% of yrsJan 1Jan 16Jan 25Jan 31Feb 4Feb 11Feb 19Feb 26Mar 5
20°F64% of yrsDec 25Jan 3Jan 10Jan 16Jan 22Jan 28Feb 2Feb 9Feb 19
16°F27% of yrstoo rare for a date
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°FOct 24Oct 30Nov 1Nov 5Nov 7Nov 11Nov 14Nov 19Nov 25
32°FNov 1Nov 6Nov 11Nov 15Nov 18Nov 22Nov 26Dec 1Dec 7
28°FNov 9Nov 17Nov 22Nov 28Dec 1Dec 5Dec 11Dec 20Jan 1
24°F93% of yrsNov 25Dec 2Dec 8Dec 15Dec 23Dec 31Jan 4Jan 11Jan 27
20°F64% of yrsDec 9Dec 19Dec 27Jan 1Jan 5Jan 10Jan 16Jan 24Feb 2
16°F27% of yrstoo rare for a date

Freeze probabilities 1991–2020 at Mccomb/Pike Co/John E Lewis Airport, MS, 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 39648 →Compare Mccomb with another place →

Weather by month in Mccomb

July is the warmest month at Mccomb/Pike Co/John E Lewis Airport, MS, averaging 91°F by day and 71°F at night; January is the coldest at 60°F and 38°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From May to October the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 70% of years and April still brings one in 12% of years.

Warmth for growing adds up to 6,290 growing degree days a year (base 50°F), more than at 80% of the 96 Mississippi stations. 42% of them (2,634) have built up by the end of June, and July adds the most, 963. Precipitation totals 60.6 inches a year, most in January (6.4") and least in October (3.8"); May to September bring 43% of it.

Monthly normals 1991–2020 at Mccomb/Pike Co/John E Lewis Airport, MS
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan60386.499%10109
Feb64425.192%6155
Mar71485.570%2313
Apr77545.012%<1466
May84624.60%0716
Jun89695.20%0874
Jul91716.00%0963
Aug91715.80%0961
Sep87674.30%0807
Oct79563.88%<1544
Nov69453.976%3242
Dec62415.094%8140

Monthly normals 1991–2020 at Mccomb/Pike Co/John E Lewis Airport, MS (413 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, Brookhaven City, MS, 22 miles north of Mccomb, has a last frost 6 days later (March 17), a first frost 6 days earlier (November 12), a season 11 days shorter.

Frost dates for 39601 (Brookhaven) →

When it snows in Mccomb, Mississippi

Measurable snow is rare here: only 4 of 16 winters from 1991 to 2020 recorded 0.1 inch or more at Mccomb/Pike Co/John E Lewis Airport, MS, 3.7 miles away, so there is no typical first-snow date to plan around.

Planting calendar for 39648

What to do and when, from the 50% frost dates for Mccomb, Mississippi
WhenWhat to do
December 31 – January 14Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
January 14 – January 28Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
February 11 – February 25Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
March 11 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by August 26Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by November 4Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
November 18 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 39648 is 4 miles from Mccomb/Pike Co/John E Lewis Airport, MS, which stands at 413 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 39648 in zone 8b, the band where the coldest night of the year averaged 15 to 20°F (-9.4 to -6.7°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Mississippi →

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 8b places in Mississippi