Average Weather in December in Romanel-sur-Lausanne Switzerland
Daily high temperatures decrease by 3°F, from 41°F to 37°F, rarely falling below 29°F or exceeding 49°F.
Daily low temperatures decrease by 3°F, from 32°F to 29°F, rarely falling below 20°F or exceeding 40°F.
For reference, on August 4, the hottest day of the year, temperatures in Romanel-sur-Lausanne typically range from 58°F to 76°F, while on January 15, the coldest day of the year, they range from 28°F to 37°F.
Average High and Low Temperature in December
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on December. 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.
Average Hourly Temperature in December
The month of December in Romanel-sur-Lausanne experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 58% throughout the month.
The clearest day of the month is December 17, with clear, mostly clear, or partly cloudy conditions 44% of the time.
For reference, on November 24, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 59%, while on July 23, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 66%.
Cloud Cover Categories in December
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. In Romanel-sur-Lausanne, the chance of a wet day over the course of December is essentially constant, remaining around 33% throughout.
For reference, the year's highest daily chance of a wet day is 44% on May 26, and its lowest chance is 27% on March 3.
Over the course of December in Romanel-sur-Lausanne, the chance of a day with only rain remains an essentially constant 26% throughout, the chance of a day with mixed snow and rain remains an essentially constant 4% throughout, and the chance of a day with only snow remains an essentially constant 2% throughout.
Probability of Precipitation in December
The average sliding 31-day rainfall during December in Romanel-sur-Lausanne is essentially constant, remaining about 3.1 inches throughout, and rarely exceeding 6.2 inches or falling below 0.9 inches.
Average Monthly Rainfall in December
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. As with rainfall, we consider the liquid-equivalent snowfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day liquid-equivalent snowfall during December in Romanel-sur-Lausanne is essentially constant, remaining about 0.3 inches throughout, and rarely exceeding 0.8 inches or falling below -0.0 inches.
Average Monthly Liquid-Equivalent Snowfall in December
Over the course of December in Romanel-sur-Lausanne, the length of the day is essentially constant. The shortest day of the month is December 21, with 8 hours, 34 minutes of daylight and the longest day is December 1, with 8 hours, 51 minutes of daylight.
Hours of Daylight and Twilight in December
The earliest sunrise of the month in Romanel-sur-Lausanne is 7:56 AM on December 1 and the latest sunrise is 21 minutes later at 8:17 AM on December 31.
The earliest sunset is 4:46 PM on December 11 and the latest sunset is 10 minutes later at 4:55 PM on December 31.
Daylight saving time is observed in Romanel-sur-Lausanne during 2018, but it neither starts nor ends during December, so the entire month is in standard time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:40 AM and sets 15 hours, 50 minutes later, at 9:30 PM, while on December 21, the shortest day of the year, it rises at 8:14 AM and sets 8 hours, 34 minutes later, at 4:48 PM.
Sunrise & Sunset with Twilight in December
The chance that a given day will be muggy in Romanel-sur-Lausanne is essentially constant during December, remaining around 0% throughout.
For reference, on July 25, the muggiest day of the year, there are muggy conditions 0% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in December
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed in Romanel-sur-Lausanne is essentially constant during December, remaining within 0.2 miles per hour of 6.7 miles per hour throughout.
For reference, on April 3, the windiest day of the year, the daily average wind speed is 7.1 miles per hour, while on August 10, the calmest day of the year, the daily average wind speed is 5.7 miles per hour.
Average Wind Speed in December
Wind Direction in December
The growing season in Romanel-sur-Lausanne typically lasts for 7.1 months (217 days), from around April 2 to around November 5, rarely starting before March 10 or after April 21, and rarely ending before October 17 or after November 30.
The month of December in Romanel-sur-Lausanne is very likely fully outside of the growing season, with the chance that a given day is in the growing season gradually decreasing from 9% to 0% over the course of the month.
Time Spent in Various Temperature Bands and the Growing Season in December
The average accumulated growing degree days in Romanel-sur-Lausanne are essentially constant during December, remaining around 2,104°F throughout.
Growing Degree Days in December
The average daily incident shortwave solar energy in Romanel-sur-Lausanne is essentially constant during December, remaining within 0.1 kWh of 1.4 kWh throughout.
The lowest average daily incident shortwave solar energy during December is 1.3 kWh on December 24.
Average Daily Incident Shortwave Solar Energy in December
For the purposes of this report, the geographical coordinates of Romanel-sur-Lausanne are 46.564 deg latitude, 6.605 deg longitude, and 1,952 ft elevation.
The topography within 2 miles of Romanel-sur-Lausanne contains very significant variations in elevation, with a maximum elevation change of 1,132 feet and an average elevation above sea level of 1,957 feet. Within 10 miles also contains very significant variations in elevation (1,916 feet). Within 50 miles contains very significant variations in elevation (12,641 feet).
The area within 2 miles of Romanel-sur-Lausanne is covered by cropland (45%), artificial surfaces (39%), and trees (16%), within 10 miles by cropland (48%) and water (22%), and within 50 miles by trees (39%) and cropland (23%).
This report illustrates the typical weather in Romanel-sur-Lausanne year round, 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 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Romanel-sur-Lausanne.
For each station, the records are corrected for the elevation difference between that station and Romanel-sur-Lausanne 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 Romanel-sur-Lausanne is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Romanel-sur-Lausanne and a given station.
The stations contributing to this reconstruction are: Aéroport Genève-Cointrin (37%, 53 kilometers, southwest); Neuchatel (36%, 55 kilometers, northeast); and Sion (27%, 67 kilometers, southeast).
Time zones for aiports and weather stations are provided by AskGeo.com .