Climate and Average Weather Year Round in Cotonou Benin
In Cotonou, the wet season is overcast, the dry season is partly cloudy, and it is hot and oppressive year round. Over the course of the year, the temperature typically varies from 75°F to 89°F and is rarely below 71°F or above 91°F.
Based on the beach/pool score, the best times of year to visit Cotonou for hot-weather activities are from mid July to mid September and from mid December to mid January.
Climate in Cotonou
The hot season lasts for 3.8 months, from January 20 to May 13, with an average daily high temperature above 88°F. The hottest month of the year in Cotonou is March, with an average high of 89°F and low of 80°F.
The cool season lasts for 2.3 months, from July 4 to September 14, with an average daily high temperature below 83°F. The coldest month of the year in Cotonou is August, with an average low of 75°F and high of 81°F.
Average High and Low Temperature in Cotonou
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature in Cotonou
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
In Cotonou, 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 Cotonou begins around October 27 and lasts for 3.5 months, ending around February 12.
The clearest month of the year in Cotonou is December, during which on average the sky is clear, mostly clear, or partly cloudy 52% of the time.
The cloudier part of the year begins around February 12 and lasts for 8.5 months, ending around October 27.
The cloudiest month of the year in Cotonou is April, during which on average the sky is overcast or mostly cloudy 85% of the time.
Cloud Cover Categories in Cotonou
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Cotonou varies very significantly throughout the year.
The wetter season lasts 6.8 months, from April 5 to October 29, with a greater than 36% chance of a given day being a wet day. The month with the most wet days in Cotonou is June, with an average of 19.4 days with at least 0.04 inches of precipitation.
The drier season lasts 5.2 months, from October 29 to April 5. The month with the fewest wet days in Cotonou is January, with an average of 1.3 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 Cotonou is June, with an average of 19.4 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 69% on June 8.
Daily Chance of Precipitation in Cotonou
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. Cotonou experiences extreme seasonal variation in monthly rainfall.
The rainy period of the year lasts for 9.5 months, from February 7 to November 23, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in Cotonou is June, with an average rainfall of 6.4 inches.
The rainless period of the year lasts for 2.4 months, from November 23 to February 7. The month with the least rain in Cotonou is January, with an average rainfall of 0.2 inches.
Average Monthly Rainfall in Cotonou
The length of the day in Cotonou does not vary substantially over the course of the year, staying within 29 minutes of 12 hours throughout. In 2022, the shortest day is December 21, with 11 hours, 45 minutes of daylight; the longest day is June 21, with 12 hours, 30 minutes of daylight.
Hours of Daylight and Twilight in Cotonou
The earliest sunrise is at 6:33 AM on May 25, and the latest sunrise is 34 minutes later at 7:08 AM on February 2. The earliest sunset is at 6:29 PM on November 12, and the latest sunset is 40 minutes later at 7:09 PM on July 16.
Daylight saving time (DST) is not observed in Cotonou during 2022.
Sunrise & Sunset with Twilight in Cotonou
The figure below presents a compact representation of key lunar data for 2022. 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.
Moon Rise, Set & Phases in Cotonou
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.
Cotonou experiences some seasonal variation in the perceived humidity.
The muggier period of the year lasts for 11 months, from January 25 to December 25, during which time the comfort level is muggy, oppressive, or miserable at least 91% of the time. The month with the most muggy days in Cotonou is May, with 31.0 days that are muggy or worse.
The month with the fewest muggy days in Cotonou is February, with 27.0 days that are muggy or worse.
Humidity Comfort Levels in Cotonou
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
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 Cotonou experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 4.2 months, from June 1 to October 8, with average wind speeds of more than 8.0 miles per hour. The windiest month of the year in Cotonou is August, with an average hourly wind speed of 10.1 miles per hour.
The calmer time of year lasts for 7.8 months, from October 8 to June 1. The calmest month of the year in Cotonou is December, with an average hourly wind speed of 5.7 miles per hour.
Average Wind Speed in Cotonou
The predominant average hourly wind direction in Cotonou varies throughout the year.
The wind is most often from the west for 4.0 weeks, from June 29 to July 27, with a peak percentage of 53% on July 11. The wind is most often from the south for 11 months, from July 27 to June 29, with a peak percentage of 49% on January 1.
Wind Direction in Cotonou
Cotonou 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 3.9 months, from February 14 to June 10, with an average temperature above 82°F. The month of the year in Cotonou with the warmest water is April, with an average temperature of 84°F.
The time of year with cooler water lasts for 1.9 months, from July 17 to September 12, with an average temperature below 78°F. The month of the year in Cotonou with the coolest water is August, with an average temperature of 77°F.
Average Water Temperature in Cotonou
To characterize how pleasant the weather is in Cotonou 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 Cotonou for general outdoor tourist activities is from late July to late August, with a peak score in the first week of August.
Tourism Score in Cotonou
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 Cotonou for hot-weather activities are from mid July to mid September and from mid December to mid January, with a peak score in the first week of August.
Beach/Pool Score in Cotonou
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).
Temperatures in Cotonou are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.
Time Spent in Various Temperature Bands and the Growing Season in Cotonou
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
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.
Growing Degree Days in Cotonou
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 some seasonal variation over the course of the year.
The brighter period of the year lasts for 1.5 months, from July 24 to September 9, with an average daily incident shortwave energy per square meter above 4.8 kWh. The brightest month of the year in Cotonou is August, with an average of 5.0 kWh.
The darker period of the year lasts for 3.0 months, from March 20 to June 20, with an average daily incident shortwave energy per square meter below 4.2 kWh. The darkest month of the year in Cotonou is May, with an average of 4.0 kWh.
Average Daily Incident Shortwave Solar Energy in Cotonou
For the purposes of this report, the geographical coordinates of Cotonou are 6.365 deg latitude, 2.418 deg longitude, and 23 ft elevation.
The topography within 2 miles of Cotonou is essentially flat, with a maximum elevation change of 75 feet and an average elevation above sea level of 17 feet. Within 10 miles is essentially flat (125 feet). Within 50 miles contains only modest variations in elevation (617 feet).
The area within 2 miles of Cotonou is covered by artificial surfaces (89%) and water (11%), within 10 miles by water (70%) and artificial surfaces (11%), and within 50 miles by water (52%) and cropland (19%).
This report illustrates the typical weather in Cotonou, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 2 weather stations near enough to contribute to our estimation of the temperature and dew point in Cotonou.
For each station, the records are corrected for the elevation difference between that station and Cotonou according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Cotonou is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Cotonou and a given station.
The stations contributing to this reconstruction are:
To get a sense of how much these sources agree with each other, you can view a comparison of Cotonou and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for airports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.
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