Climate and Average Weather Year Round in West Hills United States

In West Hills, the summers are short, hot, arid, and clear and the winters are long, cool, wet, and partly cloudy. Over the course of the year, the temperature typically varies from 46°F to 87°F and is rarely below 39°F or above 96°F.

Based on the tourism score, the best time of year to visit West Hills for warm-weather activities is from early June to early October.

The hot season lasts for 2.9 months, from June 27 to September 24, with an average daily high temperature above 82°F. The hottest month of the year in West Hills is August, with an average high of 86°F and low of 63°F.

The cool season lasts for 3.8 months, from November 23 to March 15, with an average daily high temperature below 68°F. The coldest month of the year in West Hills is December, with an average low of 47°F and high of 64°F.

In West Hills, 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 West Hills begins around April 23 and lasts for 6.3 months, ending around November 2.

The clearest month of the year in West Hills is August, during which on average the sky is clear, mostly clear, or partly cloudy 90% of the time.

The cloudier part of the year begins around November 2 and lasts for 5.7 months, ending around April 23.

The cloudiest month of the year in West Hills is February, during which on average the sky is overcast or mostly cloudy 42% of the time.

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

The wetter season lasts 4.0 months, from November 26 to March 28, with a greater than 11% chance of a given day being a wet day. The month with the most wet days in West Hills is February, with an average of 5.7 days with at least 0.04 inches of precipitation.

The drier season lasts 8.0 months, from March 28 to November 26. The month with the fewest wet days in West Hills is July, with an average of 0.1 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 West Hills is February, with an average of 5.7 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 22% on February 20.

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. West Hills experiences significant seasonal variation in monthly rainfall.

The rainy period of the year lasts for 6.4 months, from October 13 to April 26, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in West Hills is February, with an average rainfall of 3.5 inches.

The rainless period of the year lasts for 5.6 months, from April 26 to October 13. The month with the least rain in West Hills is July, with an average rainfall of 0.0 inches.

The length of the day in West Hills varies significantly over the course of the year. In 2024, the shortest day is December 21, with 9 hours, 52 minutes of daylight; the longest day is June 20, with 14 hours, 26 minutes of daylight.

The earliest sunrise is at 5:42 AM on June 12, and the latest sunrise is 1 hour, 34 minutes later at 7:15 AM on November 2. The earliest sunset is at 4:44 PM on December 4, and the latest sunset is 3 hours, 26 minutes later at 8:10 PM on June 29.

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

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.

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 West Hills, 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 2% of 2% throughout.

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 West Hills experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 6.1 months, from November 2 to May 4, with average wind speeds of more than 7.2 miles per hour. The windiest month of the year in West Hills is December, with an average hourly wind speed of 9.1 miles per hour.

The calmer time of year lasts for 5.9 months, from May 4 to November 2. The calmest month of the year in West Hills is August, with an average hourly wind speed of 5.1 miles per hour.

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

The wind is most often from the west for 6.3 months, from March 28 to October 6, with a peak percentage of 50% on May 23. The wind is most often from the north for 5.7 months, from October 6 to March 28, with a peak percentage of 53% on January 1.

West Hills 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 3.3 months, from July 5 to October 14, with an average temperature above 66°F. The month of the year in West Hills with the warmest water is August, with an average temperature of 68°F.

The time of year with cooler water lasts for 4.8 months, from December 10 to May 3, with an average temperature below 60°F. The month of the year in West Hills with the coolest water is February, with an average temperature of 58°F.

To characterize how pleasant the weather is in West Hills 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 West Hills for general outdoor tourist activities is from early June to early October, with a peak score in the third week of July.

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 West Hills for hot-weather activities is from mid July to early September, with a peak score in the last week of August.

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).

Temperatures in West Hills 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.

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.

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 3.9 months, from April 24 to August 21, with an average daily incident shortwave energy per square meter above 7.4 kWh. The brightest month of the year in West Hills is June, with an average of 8.5 kWh.

The darker period of the year lasts for 3.2 months, from November 5 to February 12, with an average daily incident shortwave energy per square meter below 4.0 kWh. The darkest month of the year in West Hills is December, with an average of 3.0 kWh.

For the purposes of this report, the geographical coordinates of West Hills are 34.197 deg latitude, -118.644 deg longitude, and 869 ft elevation.

The topography within 2 miles of West Hills contains very significant variations in elevation, with a maximum elevation change of 820 feet and an average elevation above sea level of 962 feet. Within 10 miles contains very significant variations in elevation (3,593 feet). Within 50 miles also contains extreme variations in elevation (9,111 feet).

The area within 2 miles of West Hills is covered by artificial surfaces (79%) and shrubs (18%), within 10 miles by shrubs (51%) and artificial surfaces (35%), and within 50 miles by shrubs (35%) and water (32%).