Fall Weather in Milpitas California, United StatesDaily high temperatures decrease by 20°F, from 82°F to 62°F, rarely falling below 56°F or exceeding 93°F. Daily low temperatures decrease by 14°F, from 60°F to 45°F, rarely falling below 38°F or exceeding 64°F. For reference, on August 23, the hottest day of the year, temperatures in Milpitas typically range from 60°F to 83°F, while on December 30, the coldest day of the year, they range from 43°F to 58°F. The figure below shows you a compact characterization of the hourly average fall temperatures. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day. Canguçu, Rio Grande do Sul, Brazil (6,528 miles away); Stellenbosch, Western Cape, South Africa (10,249 miles); and Adelaide, South Australia, Australia (8,099 miles) are the far-away foreign places with temperatures most similar to Milpitas (view comparison). CloudsThe fall in Milpitas experiences very rapidly increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 11% to 50%. The clearest day of the fall is September 1, with clear, mostly clear, or partly cloudy conditions 89% of the time. For reference, on January 11, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 56%, while on July 28, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 91%. PrecipitationA wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Milpitas, the chance of a wet day over the course of the fall is very rapidly increasing, starting the season at 1% and ending it at 24%. For reference, the year's highest daily chance of a wet day is 30% on February 21, and its lowest chance is -0% on July 21. RainfallTo show variation within the season and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day. The average sliding 31-day rainfall during the fall in Milpitas is very rapidly increasing, starting the season at 0.1 inches, when it rarely exceeds 0.2 inches, and ending the season at 3.0 inches, when it rarely exceeds 6.1 inches or falls below 0.5 inches. SunOver the course of the fall in Milpitas, the length of the day is very rapidly decreasing. From the start to the end of the season, the length of the day decreases by 3 hours, 10 minutes, implying an average daily decrease of 2 minutes, 7 seconds, and weekly decrease of 14 minutes, 47 seconds. The shortest day of the fall is November 30, with 9 hours, 47 minutes of daylight and the longest day is September 1, with 12 hours, 57 minutes of daylight. The latest sunrise of the fall in Milpitas is 7:34 AM on November 2 and the earliest sunrise is 59 minutes earlier at 6:35 AM on November 3. The latest sunset is 7:35 PM on September 1 and the earliest sunset is 2 hours, 46 minutes earlier at 4:49 PM on November 30. Daylight saving time (DST) ends at 1:00 AM on November 3, 2024, shifting sunrise and sunset to be an hour earlier. For reference, on June 20, the longest day of the year, the Sun rises at 5:46 AM and sets 14 hours, 45 minutes later, at 8:31 PM, while on December 21, the shortest day of the year, it rises at 7:18 AM and sets 9 hours, 35 minutes later, at 4:53 PM. 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. MoonThe figure below presents a compact representation of key lunar data for the fall of 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. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon. HumidityWe 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 chance that a given day will be muggy in Milpitas is essentially constant during the fall, remaining around 0% throughout. For reference, on September 8, the muggiest day of the year, there are muggy conditions 0% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time. WindThis 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 Milpitas is gradually decreasing during the fall, decreasing from 7.3 miles per hour to 6.8 miles per hour over the course of the season. For reference, on June 7, the windiest day of the year, the daily average wind speed is 8.7 miles per hour, while on October 20, the calmest day of the year, the daily average wind speed is 6.1 miles per hour. The lowest daily average wind speed during the fall is 6.1 miles per hour on October 20. The wind direction in Milpitas during the fall is predominantly out of the west from September 1 to November 16 and the north from November 16 to November 30. Water TemperatureMilpitas 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 surface water temperature in Milpitas is gradually decreasing during the fall, falling by 3°F, from 58°F to 55°F, over the course of the season. The highest average surface water temperature during the fall is 58°F on September 16. Growing SeasonDefinitions 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). While it does not do so every year, freezing temperatures are seen in Milpitas over some winters. The day least likely to be in the growing season is January 1, with a 75% chance. 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. The average accumulated growing degree days in Milpitas are very rapidly increasing during the fall, increasing by 1,156°F, from 2,826°F to 3,982°F, over the course of the season. Solar EnergyThis 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 in Milpitas is very rapidly decreasing during the fall, falling by 4.4 kWh, from 6.9 kWh to 2.5 kWh, over the course of the season. TopographyFor the purposes of this report, the geographical coordinates of Milpitas are 37.428 deg latitude, -121.907 deg longitude, and 16 ft elevation. The topography within 2 miles of Milpitas contains only modest variations in elevation, with a maximum elevation change of 217 feet and an average elevation above sea level of 30 feet. Within 10 miles contains only modest variations in elevation (3,294 feet). Within 50 miles also contains extreme variations in elevation (4,324 feet). The area within 2 miles of Milpitas is covered by artificial surfaces (89%), within 10 miles by artificial surfaces (50%) and grassland (27%), and within 50 miles by water (27%) and grassland (21%). Data SourcesThis report illustrates the typical weather in Milpitas, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016. Temperature and Dew PointThere are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Milpitas. For each station, the records are corrected for the elevation difference between that station and Milpitas 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 Milpitas is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Milpitas 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 Milpitas 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 DataAll 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. DisclaimerThe 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. |