USDA Hardiness Zone 9b
Frost Dates for 70665 — Sulphur, Louisiana
NOAA 1991–2020 normals from Lake Charles, LA (13 ft), 13 miles east.
Updated
In Sulphur, the last spring frost (32°F) is around February 14 in half of years and has passed by March 11 in nine years out of ten. The first fall frost comes around December 7, as early as November 14 one year in ten, leaving a typical freeze-free season of 299 days (NOAA, Lake Charles, LA).
- Last spring frost
- February 14
- First fall frost
- December 7
- Growing season
- 299 days
- Hardiness zone
- 9b
50% probability
50% probability
freeze-free, 50%
25 to 30°F (-3.9 to -1.1°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 0%
- Snow per year
- 0"
median, 1991–2020
median, 1991–2020
0 of 16 observed
NOAA normal
Frost risk by date in Sulphur
Half of springs at Lake Charles, LA see their last 32°F night by February 14; only one in ten is past it by January 16, and one in ten still has one after March 11. Planting tender crops after February 26 leaves a 30% risk of a frost on them, after March 4 20%, and after March 11 10%. The 25 days between the even-odds date and the one-in-ten date is wider than at 69% of the 88 Louisiana 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 December 7 in half of years, as early as November 14 one year in ten, and holds off past January 7 one year in ten. A hard freeze of 28°F follows 27 days later, around January 3; in spring the one-in-ten date for 28°F is February 28, 11 days before the 32°F one. The freeze-free season lasts 299 days in a typical year, longer than at 78% of the 88 Louisiana stations; it reaches 333 days one year in ten and falls short of 262 one year in ten. On average 11 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 16 days longer, to about March 2, and return around November 23. A 24°F night is unusual: 38% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Feb 8 | Feb 18 | Feb 23 | Feb 28 | Mar 2 | Mar 6 | Mar 11 | Mar 16 | Mar 24 |
| 32°F99% of yrs | Jan 16 | Jan 25 | Jan 31 | Feb 6 | Feb 14 | Feb 21 | Feb 26 | Mar 4 | Mar 11 |
| 28°F83% of yrs | Dec 31 | Jan 9 | Jan 16 | Jan 21 | Jan 27 | Jan 31 | Feb 6 | Feb 15 | Feb 28 |
| 24°F38% of yrs | too rare for a date | ||||||||
| 20°F9% of yrs | too rare for a date | ||||||||
| 16°F0% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 4 | Nov 10 | Nov 14 | Nov 19 | Nov 23 | Nov 26 | Dec 1 | Dec 5 | Dec 13 |
| 32°F99% of yrs | Nov 14 | Nov 23 | Nov 28 | Dec 3 | Dec 7 | Dec 14 | Dec 22 | Jan 1 | Jan 7 |
| 28°F83% of yrs | Dec 3 | Dec 13 | Dec 22 | Dec 29 | Jan 3 | Jan 7 | Jan 13 | Jan 20 | Feb 1 |
| 24°F38% of yrs | too rare for a date | ||||||||
| 20°F9% of yrs | too rare for a date | ||||||||
| 16°F0% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Lake Charles, LA, 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 70665 →Compare Sulphur with another place →
Weather by month in Sulphur
August is the warmest month at Lake Charles, LA, averaging 93°F by day and 75°F at night; January is the coldest at 63°F and 43°F. From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 56% of years and March still brings one in 25% of years.
Warmth for growing adds up to 7,393 growing degree days a year (base 50°F), more than at 89% of the 88 Louisiana stations. 43% of them (3,162) have built up by the end of June, and August adds the most, 1,052. Precipitation totals 59.8 inches a year, most in June (6.5") and least in February (3.3"); May to September bring 48% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 63 | 43 | 5.9 | 87% | 5 | 171 |
| Feb | 67 | 47 | 3.3 | 56% | 2 | 223 |
| Mar | 73 | 53 | 3.7 | 25% | 1 | 413 |
| Apr | 79 | 59 | 4.4 | 0% | 0 | 575 |
| May | 85 | 67 | 5.4 | 0% | 0 | 817 |
| Jun | 91 | 74 | 6.5 | 0% | 0 | 963 |
| Jul | 92 | 76 | 5.7 | 0% | 0 | 1051 |
| Aug | 93 | 75 | 6.2 | 0% | 0 | 1052 |
| Sep | 89 | 71 | 5.2 | 0% | 0 | 901 |
| Oct | 82 | 60 | 4.8 | 1% | 0 | 659 |
| Nov | 72 | 51 | 4.1 | 34% | 1 | 355 |
| Dec | 65 | 45 | 4.6 | 70% | 3 | 212 |
Monthly normals 1991–2020 at Lake Charles, LA (13 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, Moss Bluff 2 NNW, LA, 18 miles northeast of Sulphur, has a last frost 16 days later (March 2), a first frost 12 days earlier (November 25), a season 32 days shorter.
When it snows in Sulphur, Louisiana
Measurable snow is rare here: only 0 of 16 winters from 1991 to 2020 recorded 0.1 inch or more at Lake Charles Port, LA, 11.2 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 70665
| When | What to do |
|---|---|
| December 6 – December 20 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| December 20 – January 3 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| January 17 – January 31 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| February 14 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 14 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 23 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| December 7 onward | Plant 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 70665 is 13 miles from Lake Charles, LA, which stands at 13 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 70605 (Lake Charles). The 2023 USDA Plant Hardiness Zone Map lists ZIP 70665 in zone 9b, the band where the coldest night of the year averaged 25 to 30°F (-3.9 to -1.1°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across Louisiana →
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.