Chalmette, Louisiana climate: Normal weather by month, frost dates and records
Chalmette's normal year runs from 44°F January nights to 92°F August afternoons, with 70.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 21.1°C, January lows of 6°C, August highs of 33°C, 1,788 mm of precipitation a year.
- NOAA stationChalmette
- Station IDUSC00166130
- Location29.95°N 89.99°W
- Elevation3 ft (1 m)
- From the center1 miles
- Population (census place)22,447
On October 22, the normal high in Chalmette is 79°F and the normal low 62°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Chalmette.
- Jan 62° 44°
- Feb 66° 47°
- Mar 73° 53°
- Apr 79° 60°
- May 87° 68°
- Jun 91° 74°
- Jul 92° 76°
- Aug 92° 76°
- Sep 88° 73°
- Oct 81° 64°
- Nov 72° 52°
- Dec 65° 46°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Chalmette each month?
August is the warmest month, with normal highs of 92°F; January the coldest, with normal lows of 44°F. The most precipitation falls in July (8.97 in), the least in November (4.28 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 62°F | 44°F | 52.7°F | 5.84 | – | <1 | 5 | 10 h 20 min |
| February | 66°F | 47°F | 56.2°F | 4.61 | – | <1 | <1 | 11 h 10 min |
| March | 73°F | 53°F | 62.6°F | 4.90 | – | <1 | <1 | 12 h |
| April | 79°F | 60°F | 69.9°F | 5.31 | – | <1 | <1 | 12 h 50 min |
| May | 87°F | 68°F | 77.1°F | 6.32 | – | 16 | <1 | 13 h 40 min |
| June | 91°F | 74°F | 82.6°F | 7.96 | – | 24 | <1 | 14 h |
| July | 92°F | 76°F | 83.7°F | 8.97 | – | 26 | <1 | 13 h 50 min |
| August | 92°F | 76°F | 84.2°F | 7.41 | – | 27 | <1 | 13 h 20 min |
| September | 88°F | 73°F | 80.5°F | 5.19 | – | 20 | <1 | 12 h 20 min |
| October | 81°F | 64°F | 72.6°F | 4.72 | – | 5 | <1 | 11 h 30 min |
| November | 72°F | 52°F | 61.9°F | 4.28 | – | <1 | 1 | 10 h 40 min |
| December | 65°F | 46°F | 55.3°F | 4.87 | – | <1 | 1 | 10 h 10 min |
| Year (annual) | 79°F | 61°F | 69.9°F | 70.38 | – | 119 | 6 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 17°C | 6°C | 11.5°C | 148 mm |
| February | 19°C | 8°C | 13.4°C | 117 mm |
| March | 23°C | 11°C | 17.0°C | 124 mm |
| April | 26°C | 16°C | 21.1°C | 135 mm |
| May | 30°C | 20°C | 25.1°C | 161 mm |
| June | 33°C | 24°C | 28.1°C | 202 mm |
| July | 33°C | 24°C | 28.7°C | 228 mm |
| August | 33°C | 25°C | 29.0°C | 188 mm |
| September | 31°C | 23°C | 26.9°C | 132 mm |
| October | 27°C | 18°C | 22.6°C | 120 mm |
| November | 22°C | 11°C | 16.6°C | 109 mm |
| December | 18°C | 8°C | 12.9°C | 124 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00166130; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Chalmette?
Normal highs sit between 65°F and 85°F in February, March, April, October and November.
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00166130.
When is the last frost in Chalmette?
In Chalmette, the last spring frost (32°F) comes after February 10 in half of years and after March 8 in one year in ten; the first autumn frost comes before December 17 in half of years and before November 21 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- February 101 year in 10 after March 8; 9 in 10 after January 12
- First autumn frost, half of years before
- December 171 year in 10 before November 21; 9 in 10 before January 14
NOAA puts the median frost-free season at 309 days, and the season without a hard freeze (28°F) at 340 days.
A hard freeze (28°F) comes after January 26 in half of springs and before January 2 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Chalmette in zone 9b across its 2 ZIP code areas (9b in 70043, the largest).
Frost dates for every NOAA station in Louisiana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00166130; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each Chalmette ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Chalmette's 2 ZIP code areas are all in zone 9b. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Chalmette?
In a normal year in Chalmette, 119 days a year reach 90°F and 6 nights fall to 32°F or colder.
- Days at 90°F or more
- 119a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 6a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00166130.
How sunny is Chalmette?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Chalmette, 4.7 kWh per square metre a day. May is the sunniest month (85%) and December the cloudiest (72%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 73% | 3.0 |
| February | 72% | 3.6 |
| March | 78% | 4.8 |
| April | 81% | 5.7 |
| May | 85% | 6.4 |
| June | 81% | 6.2 |
| July | 77% | 5.7 |
| August | 77% | 5.3 |
| September | 81% | 5.0 |
| October | 84% | 4.4 |
| November | 81% | 3.5 |
| December | 72% | 2.7 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Chalmette need?
A normal year in Chalmette brings 1,289 heating degree days, 76% fewer than the median U.S. place (5,373), and 3,111 cooling degree days, 3.4 times the median (908). Two months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 7,457 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 391 | 11 |
| February | 253 | 7 |
| March | 141 | 67 |
| April | 18 | 163 |
| May | 0 | 375 |
| June | 0 | 528 |
| July | 0 | 580 |
| August | 0 | 593 |
| September | 0 | 463 |
| October | 13 | 249 |
| November | 154 | 60 |
| December | 319 | 17 |
| Year (annual) | 1,289 | 3,111 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00166130. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Chalmette been warmer than normal lately?
2025 averaged 71.2°F, 1.3°F above the 1991-2020 normal of 69.9°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 70.5°F | +0.6°F | 102.49 |
| 2022 | 70.0°F | +0.1°F | 69.55 |
| 2023 | 72.2°F | +2.3°F | 49.24 |
| 2024 | 71.7°F | +1.8°F | 93.15 |
| 2025 | 71.2°F | +1.3°F | 65.11 |
Source: observed years: ACIS, station USC00166130. A year counts only with all twelve months complete.
How does Chalmette's climate compare?
Chalmette is warmer than 58 of the other 64 places with their own NOAA record in Louisiana, and wetter than 61. Across the 7,247 U.S. stations with normals, its annual mean of 69.9°F is warmer than 95%.
In the Köppen classification computed from these normals, Chalmette is Cfa: temperate, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Chalmette share this climate record?
2 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Meraux, LA7,492 people · 4 mi E
- Arabi, LA4,436 people · 1 mi NW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Chalmette's climate
What is the coldest month in Chalmette?
January, with a normal high of 62°F and a normal low of 44°F. The warmest is August (92°F by day, 76°F at night).
What is the rainiest month in Chalmette?
July, with 8.97 in of precipitation in a normal year; the driest is November with 4.28 in.
What plant hardiness zone is Chalmette in?
The USDA's 2023 map puts Chalmette in zone 9b across its 2 ZIP code areas (9b in 70043, the largest).
How late can frost come in Chalmette?
In half of years the last 32°F night comes after February 10; in one year in ten it comes after March 8. Waiting until March 8 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Louisiana climateThe statewide normals and every place in the state
- Terrytown, LA4 miles from this station, 70.3°F a year
- St Bernard, LA11 miles from this station, 68.6°F a year
- Marrero, LA14 miles from this station, 68.4°F a year
- New Orleans, LA16 miles from this station, 70.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made