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Average Weather in Lerwick United Kingdom

In Lerwick, the summers are short, cool, and windy; the winters are long, very cold, wet, and extremely windy; and it is mostly cloudy year round. Over the course of the year, the temperature typically varies from 37°F to 59°F and is rarely below 30°F or above 63°F.

Based on the tourism score, the best time of year to visit Lerwick for warm-weather activities is from mid July to late August.

Climate Summary

very coldcoldcoolcoldJanFebMarAprMayJunJulAugSepOctNovDec46%46%28%28%overcastclearprecipitation: 3.6 inprecipitation: 3.6 in1.5 in1.5 inmuggy: 0%muggy: 0%drydrytourism score: 4.2tourism score: 4.20.00.0
Click on each chart for more information.

Temperature

The warm season lasts for 2.7 months, from June 24 to September 14, with an average daily high temperature above 56°F. The hottest day of the year is August 6, with an average high of 59°F and low of 52°F.

The cool season lasts for 4.4 months, from November 26 to April 8, with an average daily high temperature below 46°F. The coldest day of the year is February 17, with an average low of 37°F and high of 43°F.

Average High and Low Temperature

The daily average high (red line) and low (blue line) temperature, 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

Average Hourly Temperature in LerwickJanFebMarAprMayJunJulAugSepOctNovDec12 AM4 AM8 AM12 PM4 PM8 PM12 AMvery coldvery coldcoldcool
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
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.

Sitka, Alaska, United States (3,968 miles away) and Stanley, Falkland Islands (8,352 miles) are the far-away foreign places with temperatures most similar to Lerwick (view comparison).

Clouds

In Lerwick, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.

The clearer part of the year in Lerwick begins around April 5 and lasts for 6.2 months, ending around October 11. On May 30, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 46% of the time, and overcast or mostly cloudy 54% of the time.

The cloudier part of the year begins around October 11 and lasts for 5.8 months, ending around April 5. On March 1, the cloudiest day of the year, the sky is overcast or mostly cloudy 72% of the time, and clear, mostly clear, or partly cloudy 28% of the time.

Cloud Cover Categories

Cloud Cover Categories in LerwickclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%May 3046%May 3046%Mar 128%Mar 128%Apr 537%Apr 537%Oct 1137%Oct 1137%clearmostly clearpartly cloudymostly cloudyovercast
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds.

Precipitation

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

The wetter season lasts 6.7 months, from September 6 to March 28, with a greater than 36% chance of a given day being a wet day. The chance of a wet day peaks at 50% on January 1.

The drier season lasts 5.3 months, from March 28 to September 6. The smallest chance of a wet day is 23% on May 25.

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 49% on November 9.

Daily Chance of Precipitation

Daily Chance of Precipitation in LerwickwetwetdryJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Jan 150%Jan 150%May 2523%May 2523%Sep 636%Sep 636%Mar 2836%Mar 2836%rain
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 of the year. Lerwick experiences significant seasonal variation in monthly rainfall.

Rain falls throughout the year in Lerwick. The most rain falls during the 31 days centered around November 2, with an average total accumulation of 3.6 inches.

The least rain falls around May 13, with an average total accumulation of 1.5 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.

Sun

The length of the day in Lerwick varies extremely over the course of the year. In 2018, the shortest day is December 21, with 5 hours, 49 minutes of daylight; the longest day is June 21, with 18 hours, 56 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 3:38 AM on June 19, and the latest sunrise is 5 hours, 31 minutes later at 9:09 AM on December 27. The earliest sunset is at 2:56 PM on December 16, and the latest sunset is 7 hours, 38 minutes later at 10:34 PM on June 23.

Daylight saving time (DST) is observed in Lerwick during 2018, starting in the spring on March 25, lasting 7.1 months, and ending in the fall on October 28.

Sunrise & Sunset with Twilight and Daylight Saving Time

Sunrise & Sunset with Twilight and Daylight Saving Time in LerwickJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 193:38 AMJun 193:38 AM10:34 PMJun 2310:34 PMJun 23Dec 162:56 PMDec 162:56 PM9:09 AMDec 279:09 AMDec 27Mar 25DSTMar 25DSTDSTOct 28DSTOct 28daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunriseSunset
The solar day over the course of the year 2018. 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.

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 Lerwick, 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, remaining a virtually constant 0% throughout.

Humidity Comfort Levels

Humidity Comfort Levels in LerwickJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Jul 30%Jul 30%drydrycomfortablecomfortable
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point.

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 Lerwick experiences extreme seasonal variation over the course of the year.

The windier part of the year lasts for 6.6 months, from September 22 to April 8, with average wind speeds of more than 18.4 miles per hour. The windiest day of the year is January 23, with an average hourly wind speed of 23.5 miles per hour.

The calmer time of year lasts for 5.4 months, from April 8 to September 22. The calmest day of the year is July 13, with an average hourly wind speed of 13.3 miles per hour.

Average Wind Speed

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 Lerwick varies throughout the year.

The wind is most often from the north for 1.4 months, from May 15 to June 28, with a peak percentage of 34% on June 11. The wind is most often from the west for 1.9 weeks, from June 28 to July 11 and for 4.0 days, from December 13 to December 17, with a peak percentage of 34% on December 13. The wind is most often from the south for 5.1 months, from July 11 to December 13 and for 4.9 months, from December 17 to May 15, with a peak percentage of 39% on October 12.

Wind Direction

Wind Direction in LerwickSNWSSJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%westsouthnortheast
northeastsouthwest
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1.0 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Water Temperature

Lerwick 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 2.4 months, from July 11 to September 24, with an average temperature above 53°F. The day of the year with the warmest water is August 13, with an average temperature of 55°F.

The time of year with cooler water lasts for 4.5 months, from December 30 to May 15, with an average temperature below 47°F. The day of the year with the coolest water is March 10, with an average temperature of 45°F.

Average Water Temperature

The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.

Best Time of Year to Visit

To characterize how pleasant the weather is in Lerwick 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 Lerwick for general outdoor tourist activities is from mid July to late August, with a peak score in the first week of August.

Tourism Score

Tourism Score in LerwickJanFebMarAprMayJunJulAugSepOctNovDec02468104.24.20.00.0 precipitationprecipitationcloudscloudstemperaturetemperaturetourism score
The tourism score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F.

Beach/Pool Score

Beach/Pool Score in LerwickJanFebMarAprMayJunJulAugSepOctNovDec02468100.00.00.00.0precipitationprecipitationcloudscloudstemperaturetemperature
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

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.

Growing Season

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 Lerwick typically lasts for 8.0 months (245 days), from around April 5 to around December 6, rarely starting before February 26 or after April 29, and rarely ending before November 2 or after December 31.

Time Spent in Various Temperature Bands and the Growing Season

Time Spent in Various Temperature Bands and the Growing Season in Lerwickgrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%50%Apr 550%Apr 550%Dec 650%Dec 690%Apr 2990%Apr 2990%Nov 290%Nov 210%Feb 2610%Feb 2610%Dec 3110%Dec 310%Jan 200%Jan 20Jul 27100%Jul 27100%very coldcoldcool
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
The percentage of time spent in various temperature bands. The black line is the percentage chance that a given day is within the growing season.

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 Lerwick should appear around July 4, only rarely appearing before June 19 or after July 19.

Growing Degree Days

Growing Degree Days in LerwickJanFebMarAprMayJunJulAugSepOctNovDec0°F100°F200°F300°F400°F500°F600°F700°FJul 490°FJul 490°FDec 31497°FDec 31497°F
The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands.

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 extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 2.9 months, from May 7 to August 5, with an average daily incident shortwave energy per square meter above 4.7 kWh. The brightest day of the year is June 22, with an average of 5.9 kWh.

The darker period of the year lasts for 4.7 months, from October 14 to March 4, with an average daily incident shortwave energy per square meter below 1.3 kWh. The darkest day of the year is December 22, with an average of 0.1 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 Lerwick are 60.155 deg latitude, -1.149 deg longitude, and 69 ft elevation.

The topography within 2 miles of Lerwick contains only modest variations in elevation, with a maximum elevation change of 482 feet and an average elevation above sea level of 104 feet. Within 10 miles contains only modest variations in elevation (919 feet). Within 50 miles also contains very significant variations in elevation (1,457 feet).

The area within 2 miles of Lerwick is covered by shrubs (33%), water (30%), grassland (18%), and artificial surfaces (11%), within 10 miles by water (66%) and shrubs (11%), and within 50 miles by water (92%).

Data Sources

This report illustrates the typical weather in Lerwick, 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 Lerwick.

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

The stations contributing to this reconstruction are: Sumburgh Airport (50%, 32 kilometers, south) and Scatsa Airport (50%, 32 kilometers, north).

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 .

Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.

Disclaimer

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.