Grand Coteau, Louisiana climate: Normal weather by month, frost dates and records
Grand Coteau's normal year runs from 41°F January nights to 92°F July afternoons, with 61.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 20.2°C, January lows of 5°C, July highs of 33°C, 1,565 mm of precipitation a year.
- NOAA stationGrand Coteau
- Station IDUSC00163800
- Location30.42°N 92.04°W
- Elevation55 ft (17 m)
- From the centerunder 1 mile
- Population764
On October 23, the normal high in Grand Coteau is 79°F and the normal low 55°F, and the chance of measurable rain or snow is 26%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Grand Coteau.
- Jan 64° 41°
- Feb 67° 45°
- Mar 74° 51°
- Apr 79° 57°
- May 86° 65°
- Jun 90° 70°
- Jul 92° 73°
- Aug 92° 72°
- Sep 88° 68°
- Oct 81° 58°
- Nov 71° 48°
- Dec 65° 43°
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 Grand Coteau each month?
July is the warmest month, with normal highs of 92°F; January the coldest, with normal lows of 41°F. The most precipitation falls in June (6.97 in), the least in March (3.75 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 64°F | 41°F | 52.5°F | 6.54 | 9 | <1 | 7 | 10 h 20 min |
| February | 67°F | 45°F | 56.0°F | 4.51 | 8 | <1 | 3 | 11 h 10 min |
| March | 74°F | 51°F | 62.1°F | 3.75 | 8 | <1 | 1 | 12 h |
| April | 79°F | 57°F | 68.1°F | 5.34 | 7 | <1 | <1 | 12 h 50 min |
| May | 86°F | 65°F | 75.0°F | 5.72 | 8 | 6 | <1 | 13 h 40 min |
| June | 90°F | 70°F | 80.3°F | 6.97 | 10 | 20 | <1 | 14 h 10 min |
| July | 92°F | 73°F | 82.1°F | 4.41 | 10 | 25 | <1 | 14 h |
| August | 92°F | 72°F | 82.1°F | 4.36 | 10 | 26 | <1 | 13 h 20 min |
| September | 88°F | 68°F | 78.0°F | 5.14 | 10 | 15 | <1 | 12 h 20 min |
| October | 81°F | 58°F | 69.5°F | 5.04 | 8 | 2 | <1 | 11 h 30 min |
| November | 71°F | 48°F | 59.9°F | 4.97 | 9 | <1 | 2 | 10 h 40 min |
| December | 65°F | 43°F | 54.2°F | 4.88 | 10 | <1 | 5 | 10 h 10 min |
| Year (annual) | 79°F | 58°F | 68.3°F | 61.63 | 109 | 93 | 18 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 18°C | 5°C | 11.4°C | 166 mm |
| February | 20°C | 7°C | 13.3°C | 115 mm |
| March | 23°C | 10°C | 16.7°C | 95 mm |
| April | 26°C | 14°C | 20.1°C | 136 mm |
| May | 30°C | 18°C | 23.9°C | 145 mm |
| June | 32°C | 21°C | 26.8°C | 177 mm |
| July | 33°C | 23°C | 27.8°C | 112 mm |
| August | 33°C | 22°C | 27.8°C | 111 mm |
| September | 31°C | 20°C | 25.6°C | 131 mm |
| October | 27°C | 14°C | 20.8°C | 128 mm |
| November | 22°C | 9°C | 15.5°C | 126 mm |
| December | 18°C | 6°C | 12.3°C | 124 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00163800; 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 Grand Coteau?
Normal highs sit between 65°F and 85°F in February, March, April, October, November and December. Of those, April has the fewest days with rain (7).
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 USC00163800.
When is the last frost in Grand Coteau?
In Grand Coteau, the last spring frost (32°F) comes after February 28 in half of years and after March 25 in one year in ten; the first autumn frost comes before November 23 in half of years and before November 5 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 281 year in 10 after March 25; 9 in 10 after January 31
- First autumn frost, half of years before
- November 231 year in 10 before November 5; 9 in 10 before December 16
NOAA puts the median frost-free season at 267 days, and the season without a hard freeze (28°F) at 302 days.
A hard freeze (28°F) comes after February 6 in half of springs and before December 8 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Grand Coteau in zone 9a in ZIP code 70541. By the map's own method, the average of each year's coldest night over 1991-2020, Grand Coteau's NOAA station is in zone 9a: the coldest night of a typical year reaches 22°F (23 complete years).
Frost dates for every NOAA station in Louisiana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00163800; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Grand Coteau?
In a normal year in Grand Coteau, 93 days a year reach 90°F (1 of them 100°F or more), 18 nights fall to 32°F or colder and 109 days bring measurable precipitation.
- Days at 90°F or more
- 93a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 18a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 109a normal year
The highest temperature in this station's record (since 1893) is 107°F, on August 9, 1935; the lowest is 2°F, on February 13, 1899.
The wettest calendar year on that record is 1940, with 105.50 in; the snowiest season is 1894–95, with 15.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00163800; records: ACIS (NOAA Regional Climate Centers), station USC00163800. Records use complete months only; a month missing more than three days is left out.
How sunny is Grand Coteau?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Grand Coteau, 4.6 kWh per square metre a day. October is the sunniest month (82%) and February the cloudiest (66%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 70% | 2.9 |
| February | 66% | 3.3 |
| March | 73% | 4.5 |
| April | 77% | 5.5 |
| May | 80% | 6.1 |
| June | 79% | 6.1 |
| July | 79% | 5.9 |
| August | 80% | 5.6 |
| September | 81% | 5.1 |
| October | 82% | 4.4 |
| November | 79% | 3.4 |
| December | 70% | 2.6 |
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 Grand Coteau need?
A normal year in Grand Coteau brings 1,467 heating degree days, 73% fewer than the median U.S. place (5,373), and 2,698 cooling degree days, 3.0 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 6,929 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 401 | 12 |
| February | 274 | 21 |
| March | 150 | 60 |
| April | 44 | 137 |
| May | 4 | 314 |
| June | 0 | 459 |
| July | 0 | 530 |
| August | 0 | 532 |
| September | 1 | 391 |
| October | 40 | 179 |
| November | 197 | 43 |
| December | 356 | 21 |
| Year (annual) | 1,467 | 2,698 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00163800. 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 Grand Coteau been warmer than normal lately?
2021 averaged 68.2°F, 0.1°F below the 1991-2020 normal of 68.3°F.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 68.2°F | −0.1°F | 67.29 |
Over 87 complete years from 1884 to 2021, the station's annual mean temperature rose at a fitted 1.2°F per century (+0.07°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00163800; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Grand Coteau's climate compare?
Grand Coteau is warmer than 44 of the other 64 places with their own NOAA record in Louisiana, and wetter than 36. Across the 7,247 U.S. stations with normals, its annual mean of 68.3°F is warmer than 93%.
In the Köppen classification computed from these normals, Grand Coteau 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 Grand Coteau share this climate record?
12 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.
- Opelousas, LA15,176 people · 8 mi N
- Carencro, LA12,883 people · 7 mi S
- Church Point, LA4,032 people · 10 mi W
- Sunset, LA3,167 people · 1 mi SW
- Port Barre, LA1,740 people · 11 mi NE
- Lawtell, LA1,044 people · 11 mi NW
- Arnaudville, LA999 people · 7 mi E
- Leonville, LA880 people · 5 mi NE
- Krotz Springs, LA875 people · 19 mi NE
- Washington, LA711 people · 14 mi N
- Cankton, LA580 people · 6 mi SW
- Palmetto, LA96 people · 22 mi N
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 Grand Coteau's climate
What is the coldest month in Grand Coteau?
January, with a normal high of 64°F and a normal low of 41°F. The warmest is July (92°F by day, 73°F at night).
What is the rainiest month in Grand Coteau?
June, with 6.97 in of precipitation in a normal year; the driest is March with 3.75 in.
What plant hardiness zone is Grand Coteau in?
The USDA's 2023 map puts Grand Coteau in zone 9a in ZIP code 70541. By the same method at Grand Coteau's NOAA station, the coldest night of a typical year reaches 22°F (23 years, 1991-2020): zone 9a.
How late can frost come in Grand Coteau?
In half of years the last 32°F night comes after February 28; in one year in ten it comes after March 25. Waiting until March 25 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Louisiana climateThe statewide normals and every place in the state
- Lafayette, LA15 miles from this station, 69.4°F a year
- Crowley, LA22 miles from this station, 68.2°F a year
- Eunice, LA24 miles from this station, 67.7°F a year
- St. Martinville, LA25 miles from this station, 67.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made