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Climate and Average Weather Year Round in Ketchikan Alaska, United States

In Ketchikan, the summers are cool and mostly cloudy; the winters are long, very cold, and overcast; and it is wet year round. Over the course of the year, the temperature typically varies from 31°F to 65°F and is rarely below 19°F or above 72°F.

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

Climate in Ketchikan

very coldcoldcoolcoldvery coldJanFebMarAprMayJunJulAugSepOctNovDecNowNow42%42%22%22%overcastclearprecipitation: 13.7 inprecipitation: 13.7 in4.4 in4.4 inmuggy: 0%muggy: 0%0%0%drydrytourism score: 4.1tourism score: 4.10.00.0
Ketchikan weather by month. Click on each chart for more information.

The warm season lasts for 3.0 months, from June 7 to September 7, with an average daily high temperature above 59°F. The hottest month of the year in Ketchikan is August, with an average high of 63°F and low of 53°F.

The cold season lasts for 4.3 months, from November 9 to March 19, with an average daily high temperature below 44°F. The coldest month of the year in Ketchikan is January, with an average low of 32°F and high of 39°F.

Average High and Low Temperature in Ketchikan

Average High and Low Temperature in KetchikanwarmcoldcoldJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F10°F10°F20°F20°F30°F30°F40°F40°F50°F50°F60°F60°F70°F70°F80°F80°F90°F90°F100°F100°FDec 3138°FDec 3138°FJul 3065°FJul 3065°F31°F31°F54°F54°FJun 759°FJun 759°FSep 759°FSep 759°FNov 944°FNov 944°FMar 1944°FMar 1944°F48°F48°F50°F50°F36°F36°F34°F34°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 39°F40°F43°F49°F55°F60°F63°F63°F57°F50°F42°F39°F
Temp. 35°F36°F38°F42°F49°F54°F57°F58°F53°F46°F39°F35°F
Low 32°F32°F34°F38°F44°F49°F53°F53°F48°F42°F35°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 Ketchikan

Average Hourly Temperature in KetchikanJanFebMarAprMayJunJulAugSepOctNovDec12 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 coldcoldcoolcool
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.

Askøy, Norway (4,103 miles away) is the far-away foreign place with temperatures most similar to Ketchikan (view comparison).

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© OpenStreetMap contributors

Compare Ketchikan to another city:

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In Ketchikan, 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 Ketchikan begins around April 22 and lasts for 5.0 months, ending around September 23.

The clearest month of the year in Ketchikan is August, during which on average the sky is clear, mostly clear, or partly cloudy 41% of the time.

The cloudier part of the year begins around September 23 and lasts for 7.0 months, ending around April 22.

The cloudiest month of the year in Ketchikan is December, during which on average the sky is overcast or mostly cloudy 77% of the time.

Cloud Cover Categories in Ketchikan

Cloud Cover Categories in KetchikanclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Aug 142%Aug 142%Dec 922%Dec 922%Apr 2232%Apr 2232%Sep 2332%Sep 2332%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 77%74%73%70%63%64%61%59%66%74%75%77%
Clearer 23%26%27%30%37%36%39%41%34%26%25%23%

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

The wetter season lasts 7.1 months, from September 4 to April 6, with a greater than 56% chance of a given day being a wet day. The month with the most wet days in Ketchikan is October, with an average of 21.5 days with at least 0.04 inches of precipitation.

The drier season lasts 4.9 months, from April 6 to September 4. The month with the fewest wet days in Ketchikan is July, with an average of 12.6 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 Ketchikan is October, with an average of 21.2 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 71% on October 21.

Daily Chance of Precipitation in Ketchikan

Daily Chance of Precipitation in KetchikanwetwetdryJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Oct 3073%Oct 3073%Jun 540%Jun 540%Sep 456%Sep 456%Apr 656%Apr 656%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 15.6d13.6d16.1d15.5d13.3d12.5d12.6d14.6d17.6d21.2d18.8d16.3d
Mixed 2.8d2.4d1.5d0.3d0.0d0.0d0.0d0.0d0.0d0.2d1.7d2.8d
Snow 1.2d0.6d0.3d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.2d0.7d
Any 19.5d16.6d17.9d15.8d13.3d12.5d12.6d14.6d17.6d21.5d20.7d19.8d

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. Ketchikan experiences extreme seasonal variation in monthly rainfall.

Rain falls throughout the year in Ketchikan. The month with the most rain in Ketchikan is October, with an average rainfall of 13.6 inches.

The month with the least rain in Ketchikan is June, with an average rainfall of 4.5 inches.

Average Monthly Rainfall in Ketchikan

Average Monthly Rainfall in KetchikanJanFebMarAprMayJunJulAugSepOctNovDec0 in0 in5 in5 in10 in10 in15 in15 in20 in20 inOct 2113.7 inOct 2113.7 inJun 254.4 inJun 254.4 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 10.3″8.4″7.6″6.9″5.1″4.5″4.5″6.8″10.5″13.6″12.1″10.8″

Snowfall

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

The snowy period of the year lasts for 4.7 months, from November 4 to March 25, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in Ketchikan is January, with an average snowfall of 6.3 inches.

The snowless period of the year lasts for 7.3 months, from March 25 to November 4. The least snow falls around July 26, with an average total accumulation of 0.0 inches.

Average Monthly Snowfall in Ketchikan

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 6.3″4.8″1.8″0.1″0.0″0.0″0.0″0.0″0.0″0.2″1.9″4.8″

The length of the day in Ketchikan varies extremely over the course of the year. In 2024, the shortest day is December 21, with 7 hours, 6 minutes of daylight; the longest day is June 20, with 17 hours, 27 minutes of daylight.

Hours of Daylight and Twilight in Ketchikan

Hours of Daylight and Twilight in KetchikanJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 10 minMar 1912 hr, 10 minMar 1917 hr, 27 minJun 2017 hr, 27 minJun 2012 hr, 15 minSep 2212 hr, 15 minSep 227 hr, 6 minDec 217 hr, 6 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 7.8h9.7h11.9h14.2h16.3h17.4h16.7h14.9h12.7h10.4h8.3h7.2h

The earliest sunrise is at 4:04 AM on June 17, and the latest sunrise is 4 hours, 10 minutes later at 8:13 AM on December 28. The earliest sunset is at 3:15 PM on December 13, and the latest sunset is 6 hours, 17 minutes later at 9:32 PM on June 23.

Daylight saving time (DST) is observed in Ketchikan 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 Ketchikan

Sunrise & Sunset with Twilight and Daylight Saving Time in KetchikanJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 174:04 AMJun 174:04 AM9:32 PMJun 239:32 PMJun 23Dec 133:15 PMDec 133:15 PM8:13 AMDec 288:13 AMDec 28Mar 10DSTMar 10DSTDSTNov 3DSTNov 3daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunriseSunsetNowNow
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 Ketchikan

Solar Elevation and Azimuth in KetchikanJanFebMarAprMayJunJulAugSepOctNovDec12 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 AM000101010102020303040405000010101020202030304040501158NowNow
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 Ketchikan

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 Ketchikan, 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 Ketchikan

Humidity Comfort Levels in KetchikanJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%Feb 80%Feb 80%Aug 90%Aug 90%NowNowdrydry
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 Ketchikan experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 6.4 months, from October 5 to April 18, with average wind speeds of more than 7.0 miles per hour. The windiest month of the year in Ketchikan is January, with an average hourly wind speed of 8.9 miles per hour.

The calmer time of year lasts for 5.6 months, from April 18 to October 5. The calmest month of the year in Ketchikan is July, with an average hourly wind speed of 5.1 miles per hour.

Average Wind Speed in Ketchikan

Average Wind Speed in KetchikanwindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph0 mph2 mph2 mph4 mph4 mph6 mph6 mph8 mph8 mph10 mph10 mph12 mph12 mph14 mph14 mphJan 29.0 mphJan 29.0 mphJul 185.0 mphJul 185.0 mphOct 57.0 mphOct 57.0 mphApr 187.0 mphApr 187.0 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) 8.98.47.87.05.95.45.15.36.17.58.48.8

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

The wind is most often from the south for 6.9 months, from April 5 to November 2, with a peak percentage of 45% on October 7. The wind is most often from the east for 5.1 months, from November 2 to April 5, with a peak percentage of 52% on January 1.

Wind Direction in Ketchikan

Wind Direction in KetchikanESEJanFebMarAprMayJunJulAugSepOctNovDec0%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).

Ketchikan 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 1 to September 14, with an average temperature above 54°F. The month of the year in Ketchikan with the warmest water is August, with an average temperature of 56°F.

The time of year with cooler water lasts for 4.7 months, from December 5 to April 26, with an average temperature below 45°F. The month of the year in Ketchikan with the coolest water is February, with an average temperature of 42°F.

Average Water Temperature in Ketchikan

Average Water Temperature in KetchikanwarmcoolcoolJanFebMarAprMayJunJulAugSepOctNovDec40°F40°F45°F45°F50°F50°F55°F55°F60°F60°FAug 756°FAug 756°F42°FMar 542°FMar 5Jul 154°FJul 154°FSep 1454°FSep 1454°FDec 545°FDec 545°FApr 2645°FApr 2645°FNowNow
The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.
WaterJanFebMarAprMayJunJulAugSepOctNovDec
Temperature 43°F42°F42°F44°F48°F52°F55°F56°F53°F49°F46°F44°F

To characterize how pleasant the weather is in Ketchikan 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 Ketchikan 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 Ketchikan

Tourism Score in KetchikanJanFebMarAprMayJunJulAugSepOctNovDec002244668810104.14.10.00.0NowNowtemperaturetemperature 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 Ketchikan for hot-weather activities is from late July to early August.

Beach/Pool Score in Ketchikan

Beach/Pool Score in KetchikanJanFebMarAprMayJunJulAugSepOctNovDec002244668810100.20.20.00.0NowNowtemperaturetemperaturecloudscloudsprecipitationprecipitation
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 Ketchikan typically lasts for 6.3 months (191 days), from around April 18 to around October 26, rarely starting before March 19 or after May 14, and rarely ending before October 2 or after November 20.

Time Spent in Various Temperature Bands and the Growing Season in Ketchikan

Time Spent in Various Temperature Bands and the Growing Season in Ketchikangrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%50%Apr 1850%Apr 1850%Oct 2650%Oct 2690%May 1490%May 1490%Oct 290%Oct 210%Mar 1910%Mar 1910%Nov 2010%Nov 200%Dec 240%Dec 24Jul 22100%Jul 22100%freezingvery coldcoldcoolfrigid
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 Ketchikan should appear around June 7, only rarely appearing before May 22 or after June 27.

Growing Degree Days in Ketchikan

Growing Degree Days in KetchikanJanFebMarAprMayJunJulAugSepOctNovDec0°F0°F200°F200°F400°F400°F600°F600°F800°F800°F1,000°F1,000°FJun 790°FJun 790°FDec 31787°FDec 31787°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 significant seasonal variation over the course of the year.

The brighter period of the year lasts for 3.3 months, from May 2 to August 12, with an average daily incident shortwave energy per square meter above 4.3 kWh. The brightest month of the year in Ketchikan is June, with an average of 5.2 kWh.

The darker period of the year lasts for 4.2 months, from October 15 to February 20, with an average daily incident shortwave energy per square meter below 1.3 kWh. The darkest month of the year in Ketchikan is December, with an average of 0.4 kWh.

Average Daily Incident Shortwave Solar Energy in Ketchikan

Average Daily Incident Shortwave Solar Energy in KetchikanbrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh8 kWh8 kWhJun 155.3 kWhJun 155.3 kWhDec 190.3 kWhDec 190.3 kWhMay 24.3 kWhMay 24.3 kWhAug 124.3 kWhAug 124.3 kWhOct 151.3 kWhOct 151.3 kWhFeb 201.3 kWhFeb 201.3 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) 0.51.12.13.54.85.24.94.02.61.30.60.4

For the purposes of this report, the geographical coordinates of Ketchikan are 55.342 deg latitude, -131.648 deg longitude, and 49 ft elevation.

The topography within 2 miles of Ketchikan contains large variations in elevation, with a maximum elevation change of 2,838 feet and an average elevation above sea level of 398 feet. Within 10 miles contains large variations in elevation (3,297 feet). Within 50 miles also contains extreme variations in elevation (4,977 feet).

The area within 2 miles of Ketchikan is covered by trees (61%) and water (29%), within 10 miles by trees (55%) and water (37%), and within 50 miles by trees (48%) and water (41%).

This report illustrates the typical weather in Ketchikan, 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 Ketchikan.

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

The stations contributing to this reconstruction are:

Sources mapPAKT, 99%1 mi, 30 ftPAMM, 1%15 mi, -49 ftPAHY, 0%47 mi, -49 ft© OpenStreetMap contributors

To get a sense of how much these sources agree with each other, you can view a comparison of Ketchikan 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.