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Average Weather in Ljubljana Slovenia

In Ljubljana, the temperature typically varies from 26°F to 81°F over the course of the year, and is rarely below 14°F or above 89°F.

The warm season lasts for 3.3 months, from May 31 to September 10, with an average daily high temperature above 72°F. The hottest day of the year is August 3, with an average high of 81°F and low of 59°F.

The cold season lasts for 3.5 months, from November 19 to March 2, with an average daily high temperature below 47°F. The coldest day of the year is January 13, with an average low of 26°F and high of 38°F.

Average High and Low Temperature

The daily average high (red line) and low (blue line) temperature with percentile bands, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

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

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDecfreezingfreezingchillychillycoldcoldcoolcoolcomfortablecomfortablewarmwarm
The average hourly temperature, color coded into bands: frigid < 15°F < freezing < 32°F < chilly < 45°F < cold < 55°F < cool < 65°F < comfortable < 75°F < warm < 85°F < hot < 95°F < sweltering. The shaded overlays indicate night and civil twilight.

Sun

The length of the day in Ljubljana varies significantly over the course of the year. In 2017, the shortest day is December 21, with 8 hours, 38 minutes of daylight; the longest day is June 21, with 15 hours, 46 minutes of daylight.

Hours of Daylight and Twilight

The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The earliest sunrise is at 5:10 AM on June 15, and the latest sunrise is 2 hours, 34 minutes later at 7:44 AM on January 1. The earliest sunset is at 4:16 PM on December 10, and the latest sunset is 4 hours, 41 minutes later at 8:57 PM on June 26.

Daylight saving time (DST) is observed in Ljubljana during 2017, starting in the spring on March 26, lasting 7.1 months, and ending in the fall on October 29.

Sunrise & Sunset with Twilight and Daylight Saving Time

The solar day over the course of the year 2017. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the 'DST' labels.

Clouds

In Ljubljana, 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 Ljubljana begins around June 5 and lasts for 3.7 months, ending around September 26. On August 1, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 70% of the time, and overcast or mostly cloudy 30% of the time.

The cloudier part of the year begins around September 26 and lasts for 8.3 months, ending around June 5. On November 20, the cloudiest day of the year, the sky is overcast or mostly cloudy 64% of the time, and clear, mostly clear, or partly cloudy 36% of the time.

Cloud Cover

clearerclearercloudiercloudiercloudiercloudier0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecNov 2064%Nov 2064%Aug 130%Aug 130%Jun 547%Jun 547%Sep 2647%Sep 2647%overcastovercastmostly clearmostly clearclearclear
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds: clear < 20% < mostly clear < 40% < partly cloudy < 60% < mostly cloudy < 80% < overcast.

Precipitation

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

The wetter season lasts 7.7 months, from March 30 to November 21, with a greater than 27% chance of a given day being a wet day. The chance of a wet day peaks at 37% on June 12.

The drier season lasts 4.3 months, from November 21 to March 30. The smallest chance of a wet day is 16% on January 21.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 37% on June 12.

Daily Chance of Precipitation

The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

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 in the year. Ljubljana experiences significant seasonal variation in monthly rainfall.

Rain falls throughout the year in Ljubljana. The most rain falls during the 31 days centered around October 4, with an average total accumulation of 3.9 inches.

The least rain falls around January 18, with and average total accumulation of 1.4 inches.

Average Monthly Rainfall

The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average liquid-equivalent snowfall.

Snowfall

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. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day in the year. Ljubljana experiences some seasonal variation in monthly liquid-equivalent snowfall.

The snowy period of the year lasts for 4.1 months, from November 6 to March 10, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around January 1, with an average total liquid-equivalent accumulation of 0.4 inches.

The snowless period of the year lasts for 7.9 months, from March 10 to November 6. The least snow falls around July 25, with an average total liquid-equivalent accumulation of 0.0 inches.

Average Liquid-Equivalent Monthly Snowfall

The average liquid-equivalent snowfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average rainfall.

Humidity

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.

The perceived humidity level in Ljubljana, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, staying within 4% of 4% throughout.

Humidity Comfort Levels

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecFeb 280%Feb 280%Jul 277%Jul 277%muggymuggyhumidhumidcomfortablecomfortabledrydry
The percentage of time spent at various humidity comfort levels, categorized by dew point: dry < 55°F < comfortable < 60°F < humid < 65°F < muggy < 70°F < oppressive < 75°F < miserable.

Wind

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 Ljubljana does not vary significantly over the course of the year, remaining within 0.5 miles per hour of 2.2 miles per hour throughout.

Average Wind Speed

0.0 mph0.5 mph1.0 mph1.5 mph2.0 mph2.5 mph3.0 mph3.5 mph4.0 mphJanFebMarAprMayJunJulAugSepOctNovDecFeb 52.7 mphFeb 52.7 mphAug 101.7 mphAug 101.7 mph
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

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

The wind is most often from the east for 2.7 months, from January 5 to March 28 and for 5.8 months, from June 25 to December 18, with a peak percentage of 42% on August 20. The wind is most often from the west for 2.9 months, from March 28 to June 25 and for 2.6 weeks, from December 18 to January 5, with a peak percentage of 38% on January 2.

Wind Direction

EEWWEEWW0%20%40%60%80%100%JanFebMarAprMayJunJulAugSepOctNovDecwestwestsouthsoutheasteastnorthnorth
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions (north, east, south, and west), excluding hours in which the mean wind speed is less than 1 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Solar Energy

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 very significant seasonal variation over the course of the year.

The brighter period of the year lasts for 3.5 months, from May 4 to August 19, with an average daily incident shortwave energy per square meter above 5.6 kWh. The brightest day of the year is July 9, with an average of 6.8 kWh.

The darker period of the year lasts for 3.4 months, from October 28 to February 12, with an average daily incident shortwave energy per square meter below 2.4 kWh. The darkest day of the year is December 16, with an average of 1.2 kWh.

Average Daily Incident Shortwave Solar Energy

The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

Topography

For the purposes of this report, the geographical coordinates of Ljubljana are 46.051 deg latitude, 14.505 deg longitude, and 974 ft elevation.

The topography within 2 miles of Ljubljana contains significant variations in elevation, with a maximum elevation change of 505 feet, and an average elevation above sea level of 1,008 feet. Within 10 miles contains large variations in elevation (2,766 feet). Within 50 miles contains extreme variations in elevation (9,364 feet).

The area within 2 miles of Ljubljana is covered by artificial surfaces (77%) and trees (18%), within 10 miles by trees (47%) and cropland (32%), and within 50 miles by trees (67%) and cropland (19%).

Data Sources

This report illustrates the typical weather in Ljubljana, 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Ljubljana.

For each station, the records are corrected for the elevation difference between that station and Ljubljana 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 Ljubljana is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Ljubljana and a given station.

The stations contributing to this reconstruction are: Ljubljana Jože Pučnik Airport (72%, 20 kilometers, north), Trieste (10%, 74 kilometers, southwest), Cerklje ob Krki Airport (10%, 81 kilometers, east), and Rijeka (8%, 93 kilometers, south).

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , 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 aiports and weather stations are provided by AskGeo.com .