USDA Hardiness Zone 9b
Frost Dates for 70549 — Lake Arthur, Louisiana
NOAA 1991–2020 normals from Lake Arthur 7 SW, LA (11 ft), 5 miles southwest.
Updated
In Lake Arthur, the last spring frost (32°F) is around February 10 in half of years and has passed by March 8 in nine years out of ten. The first fall frost comes around December 11, as early as November 19 one year in ten, leaving a typical freeze-free season of 307 days (NOAA, Lake Arthur 7 SW, LA).
- Last spring frost
- February 10
- First fall frost
- December 11
- Growing season
- 307 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
- 20%
- Snow per year
- 0.1"
median, 1991–2020
median, 1991–2020
3 of 15 observed
NOAA normal
Frost risk by date in Lake Arthur
Half of springs at Lake Arthur 7 SW, LA see their last 32°F night by February 10; only one in ten is past it by January 10, and one in ten still has one after March 8. Planting tender crops after February 23 leaves a 30% risk of a frost on them, after February 28 20%, and after March 8 10%. The 26 days between the even-odds date and the one-in-ten date is wider than at 76% 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 11 in half of years, as early as November 19 one year in ten, and holds off past January 15 one year in ten. A hard freeze of 28°F follows 21 days later, around January 1; in spring the one-in-ten date for 28°F is February 24, 12 days before the 32°F one. The freeze-free season lasts 307 days in a typical year, longer than at 84% of the 88 Louisiana stations; it reaches 343 days one year in ten and falls short of 273 one year in ten. On average 10 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 February 27, and return around November 26. A 24°F night is unusual: 38% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Feb 1 | Feb 11 | Feb 19 | Feb 23 | Feb 27 | Mar 2 | Mar 7 | Mar 13 | Mar 22 |
| 32°F98% of yrs | Jan 10 | Jan 23 | Jan 30 | Feb 3 | Feb 10 | Feb 16 | Feb 23 | Feb 28 | Mar 8 |
| 28°F80% of yrs | Dec 25 | Jan 5 | Jan 13 | Jan 19 | Jan 25 | Jan 31 | Feb 4 | Feb 11 | Feb 24 |
| 24°F38% of yrs | too rare for a date | ||||||||
| 20°F11% of yrs | too rare for a date | ||||||||
| 16°F1% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Nov 7 | Nov 12 | Nov 17 | Nov 21 | Nov 26 | Nov 30 | Dec 4 | Dec 8 | Dec 19 |
| 32°F98% of yrs | Nov 19 | Nov 26 | Dec 1 | Dec 6 | Dec 11 | Dec 20 | Dec 26 | Jan 1 | Jan 15 |
| 28°F80% of yrs | Dec 1 | Dec 10 | Dec 19 | Dec 27 | Jan 1 | Jan 4 | Jan 9 | Jan 17 | Feb 1 |
| 24°F38% of yrs | too rare for a date | ||||||||
| 20°F11% of yrs | too rare for a date | ||||||||
| 16°F1% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Lake Arthur 7 SW, 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 70549 →Compare Lake Arthur with another place →
Weather by month in Lake Arthur
July is the warmest month at Lake Arthur 7 SW, LA, averaging 91°F by day and 75°F at night; January is the coldest at 61°F and 44°F. From April to October the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 53% of years and March still brings one in 19% of years.
Warmth for growing adds up to 7,182 growing degree days a year (base 50°F), more than at 84% of the 88 Louisiana stations. 43% of them (3,072) have built up by the end of June, and July adds the most, 1,028. Precipitation totals 60.1 inches a year, most in June (6.2") and least in March (3.1"); May to September bring 46% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 61 | 44 | 5.6 | 78% | 5 | 161 |
| Feb | 66 | 47 | 4.2 | 53% | 2 | 208 |
| Mar | 72 | 53 | 3.1 | 19% | 1 | 397 |
| Apr | 78 | 60 | 4.8 | 0% | 0 | 559 |
| May | 84 | 68 | 4.6 | 0% | 0 | 798 |
| Jun | 90 | 73 | 6.2 | 0% | 0 | 949 |
| Jul | 91 | 75 | 5.0 | 0% | 0 | 1028 |
| Aug | 92 | 74 | 6.1 | 0% | 0 | 1026 |
| Sep | 89 | 70 | 5.9 | 0% | 0 | 879 |
| Oct | 81 | 61 | 4.5 | 0% | 0 | 644 |
| Nov | 71 | 51 | 5.3 | 27% | <1 | 343 |
| Dec | 63 | 45 | 4.8 | 64% | 3 | 191 |
Monthly normals 1991–2020 at Lake Arthur 7 SW, LA (11 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, Jennings, LA, 9 miles northeast of Lake Arthur, has a last frost 9 days later (February 19), a first frost 7 days earlier (December 4), a season 15 days shorter.
When it snows in Lake Arthur, Louisiana
Measurable snow is rare here: only 3 of 15 winters from 1991 to 2020 recorded 0.1 inch or more at Lake Arthur 7 SW, LA, 5 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 70549
| When | What to do |
|---|---|
| December 2 – December 16 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| December 16 – December 30 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| January 13 – January 27 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| February 10 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by September 18 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by November 27 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| December 11 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 70549 is 5 miles from Lake Arthur 7 SW, LA, which stands at 11 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 70549 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.