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Average Weather at San Nicholas Island California, United States

At San Nicholas Island, the summers are comfortable, arid, and mostly clear; the winters are long, cool, and partly cloudy; and it is windy year round. Over the course of the year, the temperature typically varies from 52°F to 75°F and is rarely below 47°F or above 84°F.

Climate Summary

coolcomfortablewarmcomfortablecoolJanFebMarAprMayJunJulAugSepOctNovDec90%90%58%58%clearovercastprecipitation: 2.5 inprecipitation: 2.5 in0.0 in0.0 inmuggy: 2%muggy: 2%0%0%drydrytourism score: 8.6tourism score: 8.64.84.8
Click on each chart for more information.

Based on the tourism score, the best time of year to visit San Nicholas Island for warm-weather activities is from late June to mid October.

Temperature

The warm season lasts for 3.2 months, from July 9 to October 17, with an average daily high temperature above 73°F. The hottest day of the year is August 24, with an average high of 75°F and low of 61°F.

The cool season lasts for 4.4 months, from November 30 to April 13, with an average daily high temperature below 67°F. The coldest day of the year is December 26, with an average low of 52°F and high of 65°F.

Average High and Low Temperature

Average High and Low Temperature at San Nicholas IslandwarmcoolcoolJanFebMarAprMayJunJulAugSepOctNovDec0°F10°F20°F30°F40°F50°F60°F70°F80°F90°F100°FDec 2665°FDec 2665°FAug 2475°FAug 2475°F52°F52°F61°F61°FJul 973°FJul 973°FOct 1773°FOct 1773°FApr 1367°FApr 1367°F58°F58°F59°F59°F53°F53°FLowHigh
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 at San Nicholas IslandJanFebMarAprMayJunJulAugSepOctNovDec12 AM4 AM8 AM12 PM4 PM8 PM12 AMcoolcomfortablecomfortablecoldcold
The average hourly temperature, color coded into bands: 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 shaded overlays indicate night and civil twilight.

Chosica, Peru (4,207 miles away) is the far-away foreign place with temperatures most similar to San Nicholas Island (view comparison).

Clouds

At San Nicholas Island, 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 at San Nicholas Island begins around April 26 and lasts for 6.2 months, ending around November 2. On August 23, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 90% of the time, and overcast or mostly cloudy 10% of the time.

The cloudier part of the year begins around November 2 and lasts for 5.8 months, ending around April 26. On February 23, the cloudiest day of the year, the sky is overcast or mostly cloudy 42% of the time, and clear, mostly clear, or partly cloudy 58% of the time.

Cloud Cover Categories

Cloud Cover Categories at San Nicholas IslandclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Aug 2390%Aug 2390%Feb 2358%Feb 2358%Apr 2673%Apr 2673%Nov 274%Nov 274%clearovercastmostly clearpartly cloudy
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 at San Nicholas Island varies throughout the year.

The wetter season lasts 4.3 months, from November 22 to March 31, with a greater than 10% chance of a given day being a wet day. The chance of a wet day peaks at 20% on February 20.

The drier season lasts 7.8 months, from March 31 to November 22. The smallest chance of a wet day is 0% on August 4.

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 20% on February 20.

Daily Chance of Precipitation

Daily Chance of Precipitation at San Nicholas IslandwetwetdryJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Feb 2020%Feb 2020%Aug 40%Aug 40%Jan 116%Jan 116%Nov 2210%Nov 2210%Mar 3110%Mar 3110%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. San Nicholas Island experiences significant seasonal variation in monthly rainfall.

The rainy period of the year lasts for 5.6 months, from October 30 to April 19, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around February 19, with an average total accumulation of 2.5 inches.

The rainless period of the year lasts for 6.4 months, from April 19 to October 30. The least rain falls around August 15, with an average total accumulation of 0.0 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 at San Nicholas Island varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 57 minutes of daylight; the longest day is June 20, with 14 hours, 21 minutes of daylight.

Hours of Daylight and Twilight

Hours of Daylight and Twilight at San Nicholas IslandJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 7 minMar 2012 hr, 7 minMar 2014 hr, 21 minJun 2014 hr, 21 minJun 2012 hr, 8 minSep 2212 hr, 8 minSep 229 hr, 57 minDec 219 hr, 57 minDec 21nightnightday
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 5:48 AM on June 12, and the latest sunrise is 1 hour, 31 minutes later at 7:19 AM on November 4. The earliest sunset is at 4:50 PM on December 4, and the latest sunset is 3 hours, 21 minutes later at 8:11 PM on June 29.

Daylight saving time (DST) is observed at San Nicholas Island during 2017, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.

Sunrise & Sunset with Twilight and Daylight Saving Time

Sunrise & Sunset with Twilight and Daylight Saving Time at San Nicholas IslandJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 125:48 AMJun 125:48 AM8:11 PMJun 298:11 PMJun 29Dec 44:50 PMDec 44:50 PM7:19 AMNov 47:19 AMNov 4Mar 12DSTMar 12DSTDSTNov 5DSTNov 5daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunriseSunset
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.

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 at San Nicholas Island, 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 1% of 1% throughout.

Humidity Comfort Levels

Humidity Comfort Levels at San Nicholas IslandJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Mar 200%Mar 200%Sep 112%Sep 112%humidhumidcomfortablecomfortabledrydry
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 at San Nicholas Island experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 3.5 months, from March 1 to June 16, with average wind speeds of more than 12.9 miles per hour. The windiest day of the year is April 30, with an average hourly wind speed of 14.8 miles per hour.

The calmer time of year lasts for 8.5 months, from June 16 to March 1. The calmest day of the year is October 24, with an average hourly wind speed of 11.1 miles per hour.

Average Wind Speed

Average Wind Speed at San Nicholas IslandwindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph2 mph4 mph6 mph8 mph10 mph12 mph14 mph16 mph18 mph20 mph22 mphApr 3014.8 mphApr 3014.8 mphOct 2411.1 mphOct 2411.1 mphMar 112.9 mphMar 112.9 mphJun 1612.9 mphJun 1612.9 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 at San Nicholas Island varies throughout the year.

The wind is most often from the west for 11 months, from January 6 to December 10, with a peak percentage of 87% on August 13. The wind is most often from the north for 3.9 weeks, from December 10 to January 6, with a peak percentage of 39% on January 1.

Wind Direction

Wind Direction at San Nicholas IslandWNJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%westnortheastsouth
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).

Water Temperature

San Nicholas Island 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 3.2 months, from July 16 to October 21, with an average temperature above 64°F. The day of the year with the warmest water is August 24, with an average temperature of 66°F.

The time of year with cooler water lasts for 5.3 months, from December 13 to May 22, with an average temperature below 59°F. The day of the year with the coolest water is February 18, with an average temperature of 58°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 at San Nicholas Island 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 San Nicholas Island for general outdoor tourist activities is from late June to mid October, with a peak score in the second week of September.

Tourism Score

Tourism Score at San Nicholas Islandbest timeJanFebMarAprMayJunJulAugSepOctNovDec02468108.68.64.84.8 precipitationprecipitationcloudscloudstourism 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 San Nicholas Island for hot-weather activities is from mid August to late September, with a peak score in the second week of September.

Beach/Pool Score

Beach/Pool Score at San Nicholas IslandJanFebMarAprMayJunJulAugSepOctNovDec02468103.83.80.40.4 precipitationprecipitationcloudscloudstemperaturetemperaturebeach/pool score
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).

Temperatures at San Nicholas Island are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year.

Time Spent in Various Temperature Bands and the Growing Season

Time Spent in Various Temperature Bands and the Growing Season at San Nicholas IslandJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%100%Jan 1100%Jan 1100%Jul 3100%Jul 3coldcoolcomfortablewarm
The percentage of time spent in various temperature bands: 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 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.

Growing Degree Days

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 4.0 months, from April 24 to August 24, with an average daily incident shortwave energy per square meter above 7.2 kWh. The brightest day of the year is June 27, with an average of 8.3 kWh.

The darker period of the year lasts for 3.1 months, from November 6 to February 11, with an average daily incident shortwave energy per square meter below 4.1 kWh. The darkest day of the year is December 26, with an average of 3.0 kWh.

Average Daily Incident Shortwave Solar Energy

Average Daily Incident Shortwave Solar Energy at San Nicholas IslandbrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh1 kWh2 kWh3 kWh4 kWh5 kWh6 kWh7 kWh8 kWh9 kWhJun 278.3 kWhJun 278.3 kWhDec 263.0 kWhDec 263.0 kWhApr 247.2 kWhApr 247.2 kWhAug 247.2 kWhAug 247.2 kWhNov 64.1 kWhNov 64.1 kWhFeb 114.1 kWhFeb 114.1 kWh
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 San Nicholas Island are 33.235 deg latitude, -119.453 deg longitude, and 0 ft elevation.

The topography within 2 miles of San Nicholas Island contains significant variations in elevation, with a maximum elevation change of 801 feet and an average elevation above sea level of 197 feet. Within 10 miles contains significant variations in elevation (906 feet). Within 50 miles also contains very significant variations in elevation (906 feet).

The area within 2 miles of San Nicholas Island is covered by water (49%), shrubs (25%), and grassland (16%), within 10 miles by water (93%), and within 50 miles by water (100%).

Data Sources

This report illustrates the typical weather at San Nicholas Island, 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

San Nicholas Island has a weather station that reported reliably enough during the analysis period that we have included it in our network. When available, historical temperature and dew point measurements are taken directly from this weather station. These records are obtained from NOAA's Integrated Surface Hourly data set, falling back on ICAO METAR records as required.

In the case of missing or erroneous measurements from this station, we fall back on records from nearby stations, adjusted according to typical seasonal and diurnal intra-station differences. For a given day of the year and hour of the day, the fallback station is selected to minimize the prediction error over the years for which there are measurements for both stations.

The stations on which we may fall back include but are not limited to San Clemente Island, San Clemente Island NALF; Point Mugu, Naval Air Warfare Center; Oxnard Airport; Camarillo Airport; Catalina Airport; Santa Barbara Municipal Airport; Santa Monica Municipal Airport; and Los Angeles International Airport.

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.