Climate and Average Weather Year Round in Mandeville Louisiana, United States

In Mandeville, the summers are long, hot, and oppressive; the winters are short and cold; and it is wet and partly cloudy year round. Over the course of the year, the temperature typically varies from 43°F to 91°F and is rarely below 29°F or above 96°F.

Based on the tourism score, the best times of year to visit Mandeville for warm-weather activities are from early April to mid May and from late September to late October.

The hot season lasts for 4.2 months, from May 18 to September 26, with an average daily high temperature above 85°F. The hottest month of the year in Mandeville is July, with an average high of 91°F and low of 75°F.

The cool season lasts for 2.8 months, from December 1 to February 24, with an average daily high temperature below 68°F. The coldest month of the year in Mandeville is January, with an average low of 44°F and high of 62°F.

In Mandeville, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year in Mandeville begins around September 12 and lasts for 3.1 months, ending around December 16.

The clearest month of the year in Mandeville is October, during which on average the sky is clear, mostly clear, or partly cloudy 66% of the time.

The cloudier part of the year begins around December 16 and lasts for 8.9 months, ending around September 12.

The cloudiest month of the year in Mandeville is July, during which on average the sky is overcast or mostly cloudy 55% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Mandeville varies significantly throughout the year.

The wetter season lasts 3.3 months, from June 1 to September 10, with a greater than 40% chance of a given day being a wet day. The month with the most wet days in Mandeville is July, with an average of 17.5 days with at least 0.04 inches of precipitation.

The drier season lasts 8.7 months, from September 10 to June 1. The month with the fewest wet days in Mandeville is October, with an average of 7.2 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in Mandeville is July, with an average of 17.5 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 58% on July 28.

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Mandeville experiences significant seasonal variation in monthly rainfall.

Rain falls throughout the year in Mandeville. The month with the most rain in Mandeville is July, with an average rainfall of 5.2 inches.

The month with the least rain in Mandeville is October, with an average rainfall of 3.3 inches.

The length of the day in Mandeville varies significantly over the course of the year. In 2025, the shortest day is December 21, with 10 hours, 11 minutes of daylight; the longest day is June 20, with 14 hours, 7 minutes of daylight.

The earliest sunrise is at 5:57 AM on June 11, and the latest sunrise is 1 hour, 19 minutes later at 7:16 AM on March 9. The earliest sunset is at 4:59 PM on December 1, and the latest sunset is 3 hours, 7 minutes later at 8:06 PM on June 29.

Daylight saving time (DST) is observed in Mandeville during 2025, starting in the spring on March 9, lasting 7.8 months, and ending in the fall on November 2.

The figure below presents a compact representation of key lunar data for 2025. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

Mandeville experiences extreme seasonal variation in the perceived humidity.

The muggier period of the year lasts for 6.5 months, from April 12 to October 26, during which time the comfort level is muggy, oppressive, or miserable at least 28% of the time. The month with the most muggy days in Mandeville is July, with 30.5 days that are muggy or worse.

The month with the fewest muggy days in Mandeville is January, with 1.8 days that are muggy or worse.

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Mandeville experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 7.7 months, from September 30 to May 20, with average wind speeds of more than 5.3 miles per hour. The windiest month of the year in Mandeville is March, with an average hourly wind speed of 6.4 miles per hour.

The calmer time of year lasts for 4.3 months, from May 20 to September 30. The calmest month of the year in Mandeville is July, with an average hourly wind speed of 4.3 miles per hour.

The predominant average hourly wind direction in Mandeville varies throughout the year.

The wind is most often from the south for 4.8 months, from February 25 to July 19 and for 6.0 days, from August 15 to August 21, with a peak percentage of 49% on June 2. The wind is most often from the east for 2.8 months, from August 21 to November 14, with a peak percentage of 41% on September 20. The wind is most often from the north for 3.4 months, from November 14 to February 25, with a peak percentage of 38% on January 1.

Mandeville is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.

The average water temperature experiences significant seasonal variation over the course of the year.

The time of year with warmer water lasts for 3.9 months, from May 29 to September 25, with an average temperature above 80°F. The month of the year in Mandeville with the warmest water is August, with an average temperature of 85°F.

The time of year with cooler water lasts for 3.5 months, from December 7 to March 22, with an average temperature below 65°F. The month of the year in Mandeville with the coolest water is February, with an average temperature of 60°F.

To characterize how pleasant the weather is in Mandeville throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best times of year to visit Mandeville for general outdoor tourist activities are from early April to mid May and from late September to late October, with a peak score in the last week of April.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best times of year to visit Mandeville for hot-weather activities are from early May to late June and from late August to early October, with a peak score in the first week of June.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season in Mandeville typically lasts for 9.9 months (301 days), from around February 15 to around December 13, rarely starting before January 20 or after March 14, and rarely ending before November 15 or after January 4.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms in Mandeville should appear around January 16, only rarely appearing before January 9 or after January 29.

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences significant seasonal variation over the course of the year.

The brighter period of the year lasts for 2.9 months, from April 2 to June 30, with an average daily incident shortwave energy per square meter above 5.8 kWh. The brightest month of the year in Mandeville is May, with an average of 6.5 kWh.

The darker period of the year lasts for 2.5 months, from November 16 to February 1, with an average daily incident shortwave energy per square meter below 3.7 kWh. The darkest month of the year in Mandeville is December, with an average of 3.1 kWh.

For the purposes of this report, the geographical coordinates of Mandeville are 30.358 deg latitude, -90.066 deg longitude, and 7 ft elevation.

The topography within 2 miles of Mandeville is essentially flat, with a maximum elevation change of 23 feet and an average elevation above sea level of 7 feet. Within 10 miles is also essentially flat (52 feet). Within 50 miles is essentially flat (827 feet).

The area within 2 miles of Mandeville is covered by herbaceous vegetation (39%), water (36%), and artificial surfaces (19%), within 10 miles by water (41%) and herbaceous vegetation (26%), and within 50 miles by herbaceous vegetation (46%) and water (19%).