USDA Hardiness Zone 9b
Frost Dates for 70392 — Patterson, Louisiana
NOAA 1991–2020 normals from Morgan City, LA (5 ft), 8 miles east.
Updated
A freeze (32°F) reaches Patterson in 80% of winters. When it does, the first freeze of winter comes around January 1 and the last freeze of winter around January 30; after March 5 the chance of another is under 8%.
- Last freeze
- January 30
- First freeze
- January 1
- Winters with a freeze
- 80%
- Hardiness zone
- 9b
50%, in freezing years
50%, in freezing years
32°F or below, 1991–2020
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 20 observed
NOAA normal
Frost risk by date in Patterson
In the 80% of winters that bring a 32°F night, half of winters at Morgan City, LA see their last 32°F night by January 30; only one in ten is past it by December 30, and one in ten still has one after March 5. Counting the winters with no freeze at all, the risk of a 32°F night after March 5 is under 8% and after January 30 40%. The 34 days between the even-odds date and the one-in-ten date is the widest 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 January 1 in half of years, as early as December 2 one year in ten, and holds off past February 2 one year in ten. A hard freeze of 28°F is less common: it came in 44% of winters. On average 7 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 February 15, and return around December 14. A 24°F night is unusual: 19% of winters had one.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F98% of yrs | Jan 15 | Jan 26 | Feb 1 | Feb 7 | Feb 15 | Feb 22 | Mar 1 | Mar 6 | Mar 13 |
| 32°F80% of yrs | Dec 30 | Jan 8 | Jan 18 | Jan 23 | Jan 30 | Feb 2 | Feb 9 | Feb 22 | Mar 5 |
| 28°F44% of yrs | too rare for a date | ||||||||
| 24°F19% of yrs | too rare for a date | ||||||||
| 20°F5% of yrs | too rare for a date | ||||||||
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F98% of yrs | Nov 20 | Nov 30 | Dec 5 | Dec 9 | Dec 14 | Dec 22 | Dec 30 | Jan 4 | Jan 14 |
| 32°F80% of yrs | Dec 2 | Dec 12 | Dec 21 | Dec 26 | Jan 1 | Jan 4 | Jan 9 | Jan 17 | Feb 2 |
| 28°F44% of yrs | too rare for a date | ||||||||
| 24°F19% of yrs | too rare for a date | ||||||||
| 20°F5% of yrs | too rare for a date | ||||||||
Freeze probabilities 1991–2020 at Morgan City, 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 70392 →Compare Patterson with another place →
Weather by month in Patterson
July is the warmest month at Morgan City, LA, averaging 91°F by day and 76°F at night; January is the coldest at 63°F and 45°F. From April to November the chance of a 32°F night stays under 10% each month. In spring, February still brings one in 27% of years and March still brings one in 12% of years.
Warmth for growing adds up to 7,501 growing degree days a year (base 50°F), more than at 93% of the 88 Louisiana stations. 43% of them (3,202) have built up by the end of June, and July adds the most, 1,035. Precipitation totals 58.6 inches a year, most in August (7.3") and least in February (3.3"); May to September bring 52% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 63 | 45 | 5.0 | 53% | 4 | 189 |
| Feb | 67 | 49 | 3.3 | 27% | 1 | 239 |
| Mar | 72 | 55 | 3.9 | 12% | 1 | 418 |
| Apr | 78 | 61 | 4.0 | 0% | 0 | 586 |
| May | 84 | 69 | 4.6 | 0% | 0 | 818 |
| Jun | 89 | 75 | 7.0 | 0% | 0 | 952 |
| Jul | 91 | 76 | 6.2 | 0% | 0 | 1035 |
| Aug | 90 | 76 | 7.3 | 0% | 0 | 1032 |
| Sep | 88 | 73 | 5.4 | 0% | 0 | 913 |
| Oct | 81 | 64 | 4.0 | 0% | 0 | 695 |
| Nov | 72 | 53 | 3.9 | 4% | <1 | 381 |
| Dec | 66 | 48 | 4.0 | 35% | 2 | 243 |
Monthly normals 1991–2020 at Morgan City, LA (5 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, Franklin 3 NW, LA, 16 miles northwest of Patterson, has a last frost 12 days later (February 11), a first frost 24 days earlier (December 8), a season 32 days shorter.
When it snows in Patterson, Louisiana
Measurable snow is rare here: only 0 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Morgan City, LA, 8.3 miles away, so there is no typical first-snow date to plan around.
Where these figures come from
ZIP 70392 is 8 miles from Morgan City, LA, which stands at 5 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 70380 (Morgan City). The 2023 USDA Plant Hardiness Zone Map lists ZIP 70392 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.