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Climate and Average Weather Year Round in Lake Cowichan Canada

In Lake Cowichan, the summers are short, comfortable, dry, and partly cloudy and the winters are long, very cold, wet, and mostly cloudy. Over the course of the year, the temperature typically varies from 32°F to 71°F and is rarely below 21°F or above 81°F.

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

Climate in Lake Cowichan

very coldcoldcoolcomfortablecoolcoldvery coldJanFebMarAprMayJunJulAugSepOctNovDecNowNow73%73%26%26%overcastclearprecipitation: 7.8 inprecipitation: 7.8 in0.7 in0.7 inmuggy: 0%muggy: 0%0%0%drydrytourism score: 6.1tourism score: 6.10.00.0
Lake Cowichan weather by month. Click on each chart for more information.

The warm season lasts for 2.7 months, from June 22 to September 12, with an average daily high temperature above 65°F. The hottest month of the year in Lake Cowichan is August, with an average high of 70°F and low of 53°F.

The cold season lasts for 3.9 months, from November 11 to March 7, with an average daily high temperature below 46°F. The coldest month of the year in Lake Cowichan is December, with an average low of 32°F and high of 40°F.

Average High and Low Temperature in Lake Cowichan

Average High and Low Temperature in Lake CowichanwarmcoldcoldJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F10°F10°F20°F20°F30°F30°F40°F40°F50°F50°F60°F60°F70°F70°F80°F80°F90°F90°F100°F100°FDec 2840°FDec 2840°FJul 3171°FJul 3171°F32°F32°F54°F54°FJun 2265°FJun 2265°FSep 1265°FSep 1265°FNov 1146°FNov 1146°FMar 746°FMar 746°F50°F50°F49°F49°F37°F37°F35°F35°FNowNow
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.
AverageJanFebMarAprMayJunJulAugSepOctNovDec
High 41°F44°F48°F53°F59°F64°F70°F70°F64°F54°F45°F40°F
Temp. 37°F38°F41°F45°F51°F56°F61°F61°F56°F48°F41°F36°F
Low 33°F34°F36°F39°F44°F49°F53°F53°F48°F42°F36°F32°F

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 Lake Cowichan

Average Hourly Temperature in Lake CowichanJanFebMarAprMayJunJulAugSepOctNovDec12 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AMNowNowvery coldvery coldcoldcoldcoolcomfortable
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.

Westfield, United Kingdom (4,699 miles away) and Fumay, France (4,970 miles) are the far-away foreign places with temperatures most similar to Lake Cowichan (view comparison).

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Compare Lake Cowichan to another city:

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In Lake Cowichan, 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 Lake Cowichan begins around June 6 and lasts for 3.9 months, ending around October 3.

The clearest month of the year in Lake Cowichan is August, during which on average the sky is clear, mostly clear, or partly cloudy 68% of the time.

The cloudier part of the year begins around October 3 and lasts for 8.1 months, ending around June 6.

The cloudiest month of the year in Lake Cowichan is January, during which on average the sky is overcast or mostly cloudy 73% of the time.

Cloud Cover Categories in Lake Cowichan

Cloud Cover Categories in Lake CowichanclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Aug 273%Aug 273%Jan 2026%Jan 2026%Jun 649%Jun 649%Oct 350%Oct 350%NowNowclearmostly 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.
FractionJanFebMarAprMayJunJulAugSepOctNovDec
Cloudier 73%70%68%62%54%47%33%32%42%59%69%72%
Clearer 27%30%32%38%46%53%67%68%58%41%31%28%

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

The wetter season lasts 6.4 months, from October 9 to April 22, with a greater than 34% chance of a given day being a wet day. The month with the most wet days in Lake Cowichan is November, with an average of 16.9 days with at least 0.04 inches of precipitation.

The drier season lasts 5.6 months, from April 22 to October 9. The month with the fewest wet days in Lake Cowichan is August, with an average of 3.7 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 Lake Cowichan is November, with an average of 16.0 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 55% on November 14.

Daily Chance of Precipitation in Lake Cowichan

Daily Chance of Precipitation in Lake CowichanwetwetdryJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Nov 1758%Nov 1758%Jul 309%Jul 309%Oct 934%Oct 934%Apr 2234%Apr 2234%NowNowrainmixedsnow
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).
Days ofJanFebMarAprMayJunJulAugSepOctNovDec
Rain 13.5d12.1d13.3d10.7d7.7d6.3d4.1d3.7d6.3d12.4d16.0d14.1d
Mixed 1.7d1.2d0.7d0.1d0.0d0.0d0.0d0.0d0.0d0.0d0.7d1.6d
Snow 0.8d0.5d0.1d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.3d0.8d
Any 16.0d13.8d14.1d10.8d7.7d6.3d4.1d3.7d6.3d12.4d16.9d16.5d

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. Lake Cowichan experiences extreme seasonal variation in monthly rainfall.

Rain falls throughout the year in Lake Cowichan. The month with the most rain in Lake Cowichan is November, with an average rainfall of 7.6 inches.

The month with the least rain in Lake Cowichan is July, with an average rainfall of 0.8 inches.

Average Monthly Rainfall in Lake Cowichan

Average Monthly Rainfall in Lake CowichanJanFebMarAprMayJunJulAugSepOctNovDec0 in0 in2 in2 in4 in4 in6 in6 in8 in8 in10 in10 in12 in12 in14 in14 inNov 207.6 inNov 207.6 inJul 290.7 inJul 290.7 inNowNow
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 snowfall.
JanFebMarAprMayJunJulAugSepOctNovDec
Rainfall 5.9″5.1″4.4″2.9″1.8″1.4″0.8″0.9″1.8″4.9″7.6″6.3″

Snowfall

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Lake Cowichan experiences significant seasonal variation in monthly snowfall.

The snowy period of the year lasts for 4.0 months, from November 14 to March 12, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in Lake Cowichan is December, with an average snowfall of 3.5 inches.

The snowless period of the year lasts for 8.0 months, from March 12 to November 14. The least snow falls around July 20, with an average total accumulation of 0.0 inches.

Average Monthly Snowfall in Lake Cowichan

Average Monthly Snowfall in Lake CowichansnowsnowJanFebMarAprMayJunJulAugSepOctNovDec0 in0 in2 in2 in4 in4 in6 in6 in8 in8 in10 in10 in12 in12 inDec 314.2 inDec 314.2 inJul 200.0 inJul 200.0 inNov 141.0 inNov 141.0 inMar 121.0 inMar 121.0 in
The average 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.
JanFebMarAprMayJunJulAugSepOctNovDec
Snowfall 3.4″2.3″0.8″0.0″0.0″0.0″0.0″0.0″0.0″0.1″1.0″3.5″

The length of the day in Lake Cowichan varies extremely over the course of the year. In 2024, the shortest day is December 21, with 8 hours, 15 minutes of daylight; the longest day is June 20, with 16 hours, 11 minutes of daylight.

Hours of Daylight and Twilight in Lake Cowichan

Hours of Daylight and Twilight in Lake CowichanJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 9 minMar 1912 hr, 9 minMar 1916 hr, 11 minJun 2016 hr, 11 minJun 2012 hr, 12 minSep 2212 hr, 12 minSep 228 hr, 15 minDec 218 hr, 15 minDec 21nightnightdayNowNow
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.
Hours ofJanFebMarAprMayJunJulAugSepOctNovDec
Daylight 8.8h10.2h12.0h13.8h15.3h16.1h15.7h14.3h12.5h10.7h9.2h8.3h

The earliest sunrise is at 5:12 AM on June 15, and the latest sunrise is 2 hours, 57 minutes later at 8:09 AM on December 31. The earliest sunset is at 4:19 PM on December 11, and the latest sunset is 5 hours, 4 minutes later at 9:23 PM on June 24.

Daylight saving time (DST) is observed in Lake Cowichan during 2024, starting in the spring on March 10, lasting 7.8 months, and ending in the fall on November 3.

Sunrise & Sunset with Twilight and Daylight Saving Time in Lake Cowichan

Sunrise & Sunset with Twilight and Daylight Saving Time in Lake CowichanJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 155:12 AMJun 155:12 AM9:23 PMJun 249:23 PMJun 24Dec 114:19 PMDec 114:19 PM8:09 AMDec 318:09 AMDec 31Mar 10DSTMar 10DSTDSTNov 3DSTNov 3daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunsetNowNow
The solar day over the course of the year 2024. 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.

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.

Solar Elevation and Azimuth in Lake Cowichan

Solar Elevation and Azimuth in Lake CowichanJanFebMarAprMayJunJulAugSepOctNovDec12 AM12 AM2 AM2 AM4 AM4 AM6 AM6 AM8 AM8 AM10 AM10 AM12 PM12 PM2 PM2 PM4 PM4 PM6 PM6 PM8 PM8 PM10 PM10 PM12 AM12 AM00010101010202030304040506000010101020202020303040405050601865NowNow
northeastsouthwest
Solar elevation and azimuth over the course of the year 2024. The black lines are lines of constant solar elevation (the angle of the sun above the horizon, in degrees). The background color fills indicate the azimuth (the compass bearing) of the sun. The lightly tinted areas at the boundaries of the cardinal compass points indicate the implied intermediate directions (northeast, southeast, southwest, and northwest).

The figure below presents a compact representation of key lunar data for 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.

Moon Rise, Set & Phases in Lake Cowichan

The time in which the moon is above the horizon (light blue area), with new moons (dark gray lines) and full moons (blue lines) indicated. The shaded overlays indicate night and civil twilight.

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 Lake Cowichan, 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 in Lake Cowichan

Humidity Comfort Levels in Lake CowichanJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Jan 210%Jan 210%Jul 220%Jul 220%NowNowdrydrycomfortablecomfortable
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.
JanFebMarAprMayJunJulAugSepOctNovDec
Muggy days 0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d

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 Lake Cowichan experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 6.0 months, from October 20 to April 21, with average wind speeds of more than 5.1 miles per hour. The windiest month of the year in Lake Cowichan is December, with an average hourly wind speed of 6.1 miles per hour.

The calmer time of year lasts for 6.0 months, from April 21 to October 20. The calmest month of the year in Lake Cowichan is August, with an average hourly wind speed of 3.9 miles per hour.

Average Wind Speed in Lake Cowichan

Average Wind Speed in Lake CowichanwindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph0 mph1 mph1 mph2 mph2 mph3 mph3 mph4 mph4 mph5 mph5 mph6 mph6 mph7 mph7 mph8 mph8 mph9 mph9 mph10 mph10 mphDec 36.2 mphDec 36.2 mphAug 133.9 mphAug 133.9 mphOct 205.1 mphOct 205.1 mphApr 215.1 mphApr 215.1 mphNowNow
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.
JanFebMarAprMayJunJulAugSepOctNovDec
Wind Speed (mph) 5.85.75.65.14.74.54.23.94.14.96.06.1

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

The wind is most often from the south for 2.3 weeks, from March 11 to March 27 and for 1.1 months, from October 16 to November 18, with a peak percentage of 35% on November 4. The wind is most often from the west for 6.6 months, from March 27 to October 16, with a peak percentage of 74% on July 21. The wind is most often from the east for 3.8 months, from November 18 to March 11, with a peak percentage of 45% on January 1.

Wind Direction in Lake Cowichan

Wind Direction in Lake CowichanESWSEJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%NowNowwestsoutheastnorth
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).

Lake Cowichan 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 3.0 months, from June 14 to September 16, with an average temperature above 55°F. The month of the year in Lake Cowichan with the warmest water is August, with an average temperature of 57°F.

The time of year with cooler water lasts for 4.1 months, from November 29 to April 2, with an average temperature below 48°F. The month of the year in Lake Cowichan with the coolest water is January, with an average temperature of 45°F.

Average Water Temperature in Lake Cowichan

The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.
WaterJanFebMarAprMayJunJulAugSepOctNovDec
Temperature 45°F46°F47°F49°F52°F55°F57°F57°F55°F52°F49°F47°F

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

Tourism Score in Lake Cowichan

Tourism Score in Lake CowichanJanFebMarAprMayJunJulAugSepOctNovDec002244668810106.16.10.00.0NowNowtemperaturetemperature cloudscloudsprecipitationprecipitationtourism 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. Based on this score, the best time of year to visit Lake Cowichan for hot-weather activities is from late July to mid August, with a peak score in the first week of August.

Beach/Pool Score in Lake Cowichan

Beach/Pool Score in Lake CowichanJanFebMarAprMayJunJulAugSepOctNovDec002244668810101.31.30.00.0NowNowtemperaturetemperature cloudscloudsprecipitationprecipitation
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.

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 Lake Cowichan typically lasts for 7.0 months (216 days), from around April 5 to around November 7, rarely starting before March 13 or after April 28, and rarely ending before October 19 or after November 27.

Time Spent in Various Temperature Bands and the Growing Season in Lake Cowichan

Time Spent in Various Temperature Bands and the Growing Season in Lake Cowichangrowing 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%Nov 750%Nov 790%Apr 2890%Apr 2890%Oct 1990%Oct 1910%Mar 1310%Mar 1310%Nov 2710%Nov 270%Dec 300%Dec 30Jul 28100%Jul 28100%freezingvery coldcoldcoolwarm
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 Lake Cowichan should appear around May 19, only rarely appearing before May 4 or after June 4.

Growing Degree Days in Lake Cowichan

Growing Degree Days in Lake CowichanJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F200°F200°F400°F400°F600°F600°F800°F800°F1,000°F1,000°F1,200°F1,200°F1,400°F1,400°FMay 1990°FMay 1990°FAug 22900°FAug 22900°FDec 311,222°FDec 311,222°FNowNow
The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands.

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 3.3 months, from May 11 to August 20, with an average daily incident shortwave energy per square meter above 5.6 kWh. The brightest month of the year in Lake Cowichan is July, with an average of 6.7 kWh.

The darker period of the year lasts for 4.0 months, from October 22 to February 20, with an average daily incident shortwave energy per square meter below 2.0 kWh. The darkest month of the year in Lake Cowichan is December, with an average of 0.8 kWh.

Average Daily Incident Shortwave Solar Energy in Lake Cowichan

Average Daily Incident Shortwave Solar Energy in Lake CowichanbrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWh9 kWh9 kWhJul 196.8 kWhJul 196.8 kWhDec 240.8 kWhDec 240.8 kWhMay 115.6 kWhMay 115.6 kWhOct 222.0 kWhOct 222.0 kWhFeb 202.0 kWhFeb 202.0 kWhNowNow
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.
JanFebMarAprMayJunJulAugSepOctNovDec
Solar Energy (kWh) 1.01.82.94.45.76.36.75.84.22.41.20.8

For the purposes of this report, the geographical coordinates of Lake Cowichan are 48.825 deg latitude, -124.055 deg longitude, and 571 ft elevation.

The topography within 2 miles of Lake Cowichan contains large variations in elevation, with a maximum elevation change of 2,300 feet and an average elevation above sea level of 847 feet. Within 10 miles contains large variations in elevation (4,685 feet). Within 50 miles also contains extreme variations in elevation (5,879 feet).

The area within 2 miles of Lake Cowichan is covered by trees (75%), within 10 miles by trees (90%), and within 50 miles by trees (47%) and water (44%).

This report illustrates the typical weather in Lake Cowichan, 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 Lake Cowichan.

For each station, the records are corrected for the elevation difference between that station and Lake Cowichan 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 Lake Cowichan is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Lake Cowichan 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 Lake Cowichan 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 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 © OpenStreetMap contributors.

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.

Please review our full terms contained on our Terms of Service page.