Winter Weather in Calais FranceDaily high temperatures are around 46°F, rarely falling below 35°F or exceeding 55°F. The lowest daily average high temperature is 45°F on January 18. Daily low temperatures are around 38°F, rarely falling below 27°F or exceeding 48°F. The lowest daily average low temperature is 36°F on February 8. For reference, on August 3, the hottest day of the year, temperatures in Calais typically range from 58°F to 70°F, while on February 8, the coldest day of the year, they range from 36°F to 45°F. The figure below shows you a compact characterization of the hourly average winter temperatures. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day. Point Roberts, United States (4,811 miles away) is the far-away foreign place with temperatures most similar to Calais (view comparison). CloudsThe winter in Calais experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 61% throughout the season. The highest chance of overcast or mostly cloudy conditions is 65% on December 29. The clearest day of the winter is February 27, with clear, mostly clear, or partly cloudy conditions 42% of the time. For reference, on December 29, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 65%, while on July 20, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 59%. PrecipitationA wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Calais, the chance of a wet day over the course of the winter is very rapidly decreasing, starting the season at 34% and ending it at 24%. For reference, the year's highest daily chance of a wet day is 37% on November 22, and its lowest chance is 21% on April 20. RainfallTo show variation within the season and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day. The average sliding 31-day rainfall during the winter in Calais is decreasing, starting the season at 2.2 inches, when it rarely exceeds 3.9 inches or falls below 1.1 inches, and ending the season at 1.4 inches, when it rarely exceeds 2.4 inches or falls below 0.4 inches. SunOver the course of the winter in Calais, the length of the day is very rapidly increasing. From the start to the end of the season, the length of the day increases by 2 hours, 38 minutes, implying an average daily increase of 1 minute, 47 seconds, and weekly increase of 12 minutes, 26 seconds. The shortest day of the winter is December 21, with 7 hours, 55 minutes of daylight and the longest day is February 28, with 10 hours, 53 minutes of daylight. The latest sunrise of the winter in Calais is 8:55 AM on December 30 and the earliest sunrise is 1 hour, 17 minutes earlier at 7:38 AM on February 28. The earliest sunset is 4:46 PM on December 12 and the latest sunset is 1 hour, 46 minutes later at 6:32 PM on February 28. Daylight saving time is observed in Calais during 2024, but it neither starts nor ends during the winter, so the entire season is in daylight saving time. For reference, on June 20, the longest day of the year, the Sun rises at 5:38 AM and sets 16 hours, 32 minutes later, at 10:10 PM, while on December 21, the shortest day of the year, it rises at 8:53 AM and sets 7 hours, 55 minutes later, at 4:48 PM. The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation. MoonThe figure below presents a compact representation of key lunar data for the winter of 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. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon. HumidityWe 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. The chance that a given day will be muggy in Calais is essentially constant during the winter, remaining around 0% throughout. For reference, on August 10, the muggiest day of the year, there are muggy conditions 2% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time. WindThis 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 Calais is decreasing during the winter, decreasing from 16.1 miles per hour to 15.0 miles per hour over the course of the season. For reference, on January 1, the windiest day of the year, the daily average wind speed is 17.4 miles per hour, while on August 3, the calmest day of the year, the daily average wind speed is 10.9 miles per hour. The highest daily average wind speed during the winter is 17.4 miles per hour on January 1. The wind direction in Calais during the winter is predominantly out of the south from December 1 to December 2 and the west from December 2 to February 28. Water TemperatureCalais 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 surface water temperature in Calais is rapidly decreasing during the winter, falling by 8°F, from 52°F to 45°F, over the course of the season. The lowest average surface water temperature during the winter is 45°F on February 27. Growing SeasonDefinitions 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 Calais typically lasts for 8.7 months (265 days), from around March 14 to around December 4, rarely starting before February 8 or after April 11, and rarely ending before November 2 or after December 29. The smallest chance that a given day will be within the growing season in Calais during the winter is 4% on January 15. 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. The average accumulated growing degree days in Calais are very rapidly decreasing during the winter, decreasing by 1,810°F, from 1,820°F to 10°F, over the course of the season. Solar EnergyThis 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 in Calais is increasing during the winter, rising by 1.5 kWh, from 0.8 kWh to 2.3 kWh, over the course of the season. The lowest average daily incident shortwave solar energy during the winter is 0.7 kWh on December 22. TopographyFor the purposes of this report, the geographical coordinates of Calais are 50.952 deg latitude, 1.856 deg longitude, and 20 ft elevation. The topography within 2 miles of Calais is essentially flat, with a maximum elevation change of 69 feet and an average elevation above sea level of 10 feet. Within 10 miles is essentially flat (623 feet). Within 50 miles also contains significant variations in elevation (771 feet). The area within 2 miles of Calais is covered by artificial surfaces (74%) and cropland (12%), within 10 miles by water (42%) and cropland (40%), and within 50 miles by water (54%) and cropland (31%). Data SourcesThis report illustrates the typical weather in Calais, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016. Temperature and Dew PointThere are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Calais. For each station, the records are corrected for the elevation difference between that station and Calais 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 Calais is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Calais 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 Calais 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. Other DataAll 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 © OpenStreetMap contributors. DisclaimerThe 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. Please review our full terms contained on our Terms of Service page. |