Average Weather at San Carlos Airport California, United States
At San Carlos Airport, the summers are long, warm, arid, and mostly clear and the winters are short, cold, wet, and partly cloudy. Over the course of the year, the temperature typically varies from 43°F to 78°F and is rarely below 36°F or above 90°F.
Based on the tourism score, the best time of year to visit San Carlos Airport for warm-weather activities is from late June to late September.
The warm season lasts for 4.3 months, from June 5 to October 14, with an average daily high temperature above 74°F. The hottest day of the year is August 27, with an average high of 78°F and low of 58°F.
The cool season lasts for 2.5 months, from November 28 to February 12, with an average daily high temperature below 62°F. The coldest day of the year is December 31, with an average low of 43°F and high of 57°F.
Average High and Low Temperature
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
Monte Patria, Chile (5,766 miles away); Amor, Portugal (5,637 miles); and Grabouw, South Africa (10,281 miles) are the far-away foreign places with temperatures most similar to San Carlos Airport (view comparison).
At San Carlos Airport, 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 Carlos Airport begins around May 27 and lasts for 4.9 months, ending around October 24. On August 8, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 92% of the time, and overcast or mostly cloudy 8% of the time.
The cloudier part of the year begins around October 24 and lasts for 7.1 months, ending around May 27. On January 11, the cloudiest day of the year, the sky is overcast or mostly cloudy 54% of the time, and clear, mostly clear, or partly cloudy 46% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at San Carlos Airport varies throughout the year.
The wetter season lasts 5.2 months, from November 4 to April 10, with a greater than 15% chance of a given day being a wet day. The chance of a wet day peaks at 30% on February 20.
The drier season lasts 6.8 months, from April 10 to November 4. The smallest chance of a wet day is 0% on July 19.
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 30% on February 20.
Daily Chance of Precipitation
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 Carlos Airport experiences significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 7.3 months, from October 4 to May 13, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around February 15, with an average total accumulation of 3.7 inches.
The rainless period of the year lasts for 4.7 months, from May 13 to October 4. The least rain falls around July 31, with an average total accumulation of 0.0 inches.
Average Monthly Rainfall
The length of the day at San Carlos Airport varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 34 minutes of daylight; the longest day is June 21, with 14 hours, 45 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:47 AM on June 13, and the latest sunrise is 1 hour, 49 minutes later at 7:36 AM on November 3. The earliest sunset is at 4:50 PM on December 6, and the latest sunset is 3 hours, 44 minutes later at 8:34 PM on June 28.
Daylight saving time (DST) is observed at San Carlos Airport during 2018, starting in the spring on March 11, lasting 7.8 months, and ending in the fall on November 4.
Sunrise & Sunset with Twilight and Daylight Saving Time
The perceived humidity level at San Carlos Airport, 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
The average hourly wind speed at San Carlos Airport experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 5.6 months, from February 3 to July 22, with average wind speeds of more than 8.7 miles per hour. The windiest day of the year is May 31, with an average hourly wind speed of 10.0 miles per hour.
The calmer time of year lasts for 6.4 months, from July 22 to February 3. The calmest day of the year is October 5, with an average hourly wind speed of 7.4 miles per hour.
Average Wind Speed
The predominant average hourly wind direction at San Carlos Airport varies throughout the year.
The wind is most often from the west for 9.1 months, from February 12 to November 14, with a peak percentage of 92% on August 11. The wind is most often from the north for 2.9 months, from November 14 to February 12, with a peak percentage of 34% on January 1.
San Carlos Airport 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 2.5 months, from August 2 to October 17, with an average temperature above 57°F. The day of the year with the warmest water is September 16, with an average temperature of 58°F.
The time of year with cooler water lasts for 5.8 months, from December 18 to June 11, with an average temperature below 54°F. The day of the year with the coolest water is April 29, with an average temperature of 53°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is at San Carlos Airport 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 Carlos Airport for general outdoor tourist activities is from late June to late September, with a peak score in the first week of August.
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 Carlos Airport for hot-weather activities is from late June to mid September, with a peak score in the last week of August.
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.
Temperatures at San Carlos Airport 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
Growing Degree Days
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 3.6 months, from May 7 to August 25, 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 8.4 kWh.
The darker period of the year lasts for 3.5 months, from November 4 to February 17, with an average daily incident shortwave energy per square meter below 3.4 kWh. The darkest day of the year is December 23, with an average of 2.2 kWh.
Average Daily Incident Shortwave Solar Energy
This report illustrates the typical weather at San Carlos Airport, 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 Carlos Airport 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 Francisco International Airport, Hayward Air Terminal Airport, Oakland International Airport, Naval Air Station Alameda (historical), Moffett Federal Airfield, Half Moon Bay Airport, Norman Y. Mineta San José International Airport, and Livermore Municipal Airport.
Time zones for aiports and weather stations are provided by AskGeo.com .