Climate and Average Weather Year Round in Olonne-sur-Mer France

In Olonne-sur-Mer, the summers are comfortable; the winters are long, cold, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 40°F to 74°F and is rarely below 31°F or above 83°F.

Based on the tourism score, the best time of year to visit Olonne-sur-Mer for warm-weather activities is from late June to mid September.

The warm season lasts for 3.2 months, from June 12 to September 19, with an average daily high temperature above 69°F. The hottest month of the year in Olonne-sur-Mer is August, with an average high of 73°F and low of 60°F.

The cool season lasts for 3.9 months, from November 20 to March 17, with an average daily high temperature below 54°F. The coldest month of the year in Olonne-sur-Mer is February, with an average low of 41°F and high of 50°F.

In Olonne-sur-Mer, 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 Olonne-sur-Mer begins around May 27 and lasts for 4.2 months, ending around October 2.

The clearest month of the year in Olonne-sur-Mer is July, during which on average the sky is clear, mostly clear, or partly cloudy 68% of the time.

The cloudier part of the year begins around October 2 and lasts for 7.8 months, ending around May 27.

The cloudiest month of the year in Olonne-sur-Mer is January, during which on average the sky is overcast or mostly cloudy 60% 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 Olonne-sur-Mer varies throughout the year.

The wetter season lasts 7.8 months, from September 22 to May 14, with a greater than 25% chance of a given day being a wet day. The month with the most wet days in Olonne-sur-Mer is November, with an average of 10.0 days with at least 0.04 inches of precipitation.

The drier season lasts 4.2 months, from May 14 to September 22. The month with the fewest wet days in Olonne-sur-Mer is August, with an average of 4.7 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 Olonne-sur-Mer is November, with an average of 10.0 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 35% on December 29.

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. Olonne-sur-Mer experiences some seasonal variation in monthly rainfall.

Rain falls throughout the year in Olonne-sur-Mer. The month with the most rain in Olonne-sur-Mer is October, with an average rainfall of 2.6 inches.

The month with the least rain in Olonne-sur-Mer is August, with an average rainfall of 1.0 inches.

The length of the day in Olonne-sur-Mer varies significantly over the course of the year. In 2024, the shortest day is December 21, with 8 hours, 34 minutes of daylight; the longest day is June 20, with 15 hours, 50 minutes of daylight.

The earliest sunrise is at 6:13 AM on June 16, and the latest sunrise is 2 hours, 38 minutes later at 8:51 AM on January 2. The earliest sunset is at 5:19 PM on December 10, and the latest sunset is 4 hours, 45 minutes later at 10:04 PM on June 25.

Daylight saving time (DST) is observed in Olonne-sur-Mer during 2024, starting in the spring on March 31, lasting 6.9 months, and ending in the fall on October 27.

The figure below presents a compact representation of key lunar data for 2024. 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.

Olonne-sur-Mer experiences some seasonal variation in the perceived humidity.

The muggier period of the year lasts for 3.1 months, from June 24 to September 27, during which time the comfort level is muggy, oppressive, or miserable at least 3% of the time. The month with the most muggy days in Olonne-sur-Mer is August, with 3.4 days that are muggy or worse.

The least muggy day of the year is February 29, when muggy conditions are essentially unheard of.

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 Olonne-sur-Mer experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 6.4 months, from October 7 to April 18, with average wind speeds of more than 12.1 miles per hour. The windiest month of the year in Olonne-sur-Mer is December, with an average hourly wind speed of 14.3 miles per hour.

The calmer time of year lasts for 5.6 months, from April 18 to October 7. The calmest month of the year in Olonne-sur-Mer is August, with an average hourly wind speed of 10.0 miles per hour.

The predominant average hourly wind direction in Olonne-sur-Mer varies throughout the year.

The wind is most often from the south for 1.0 weeks, from October 24 to October 31, with a peak percentage of 29% on October 28. The wind is most often from the west for 12 months, from October 31 to October 24, with a peak percentage of 32% on January 1.

Olonne-sur-Mer 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 some seasonal variation over the course of the year.

The time of year with warmer water lasts for 3.2 months, from June 23 to September 30, with an average temperature above 63°F. The month of the year in Olonne-sur-Mer with the warmest water is August, with an average temperature of 67°F.

The time of year with cooler water lasts for 3.8 months, from December 20 to April 13, with an average temperature below 53°F. The month of the year in Olonne-sur-Mer with the coolest water is February, with an average temperature of 50°F.

To characterize how pleasant the weather is in Olonne-sur-Mer 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 time of year to visit Olonne-sur-Mer for general outdoor tourist activities is from late June to mid September, with a peak score in the last week of July.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Olonne-sur-Mer for hot-weather activities is from mid July to mid August, with a peak score in the first week of August.

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 Olonne-sur-Mer typically lasts for 10 months (307 days), from around February 16 to around December 20, rarely starting after March 20, or ending before November 14.

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 Olonne-sur-Mer should appear around March 25, only rarely appearing before February 29 or after April 21.

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 extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 3.4 months, from May 8 to August 19, with an average daily incident shortwave energy per square meter above 5.9 kWh. The brightest month of the year in Olonne-sur-Mer is June, with an average of 7.0 kWh.

The darker period of the year lasts for 3.7 months, from October 26 to February 17, with an average daily incident shortwave energy per square meter below 2.3 kWh. The darkest month of the year in Olonne-sur-Mer is December, with an average of 1.1 kWh.

For the purposes of this report, the geographical coordinates of Olonne-sur-Mer are 46.535 deg latitude, -1.773 deg longitude, and 79 ft elevation.

The topography within 2 miles of Olonne-sur-Mer contains only modest variations in elevation, with a maximum elevation change of 154 feet and an average elevation above sea level of 35 feet. Within 10 miles also contains only modest variations in elevation (308 feet). Within 50 miles contains only modest variations in elevation (1,191 feet).

The area within 2 miles of Olonne-sur-Mer is covered by cropland (46%), artificial surfaces (26%), and herbaceous vegetation (18%), within 10 miles by water (42%) and cropland (38%), and within 50 miles by water (54%) and cropland (30%).