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Average Weather in Calistoga California, United States

In Calistoga, the summers are long, hot, 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 36°F to 88°F and is rarely below 27°F or above 99°F.

Based on the tourism score, the best time of year to visit Calistoga for warm-weather activities is from late June to early September.

Climate Summary

coldcoolwarmhotwarmcoolcoldJanFebMarAprMayJunJulAugSepOctNovDec91%91%41%41%clearovercastprecipitation: 5.6 inprecipitation: 5.6 in0.0 in0.0 inmuggy: 0%muggy: 0%0%0%drydrytourism score: 7.0tourism score: 7.00.40.4
Click on each chart for more information.

Temperature

The hot season lasts for 4.0 months, from June 6 to October 5, with an average daily high temperature above 81°F. The hottest day of the year is July 17, with an average high of 88°F and low of 55°F.

The cool season lasts for 2.9 months, from November 24 to February 21, with an average daily high temperature below 60°F. The coldest day of the year is January 1, with an average low of 36°F and high of 53°F.

Average High and Low Temperature

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 in CalistogaJanFebMarAprMayJunJulAugSepOctNovDec12 AM4 AM8 AM12 PM4 PM8 PM12 AMvery coldvery coldcoldcoldcoolwarmhotvery coldvery coldcomfortable
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.

Puente Alto, Chile (6,005 miles away); Sertã, Portugal (5,627 miles); and Benalla, Australia (7,801 miles) are the far-away foreign places with temperatures most similar to Calistoga (view comparison).

Clouds

In Calistoga, the average percentage of the sky covered by clouds experiences extreme seasonal variation over the course of the year.

The clearer part of the year in Calistoga begins around May 16 and lasts for 5.2 months, ending around October 23. On July 20, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 91% of the time, and overcast or mostly cloudy 9% of the time.

The cloudier part of the year begins around October 23 and lasts for 6.8 months, ending around May 16. On January 10, the cloudiest day of the year, the sky is overcast or mostly cloudy 59% of the time, and clear, mostly clear, or partly cloudy 41% of the time.

Cloud Cover Categories

Cloud Cover Categories in CalistogaclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Jul 2091%Jul 2091%Jan 1041%Jan 1041%May 1666%May 1666%Oct 2366%Oct 2366%clearovercastpartly cloudymostly clearmostly cloudy
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.

Precipitation

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

The wetter season lasts 5.4 months, from October 31 to April 10, with a greater than 17% chance of a given day being a wet day. The chance of a wet day peaks at 33% on February 20.

The drier season lasts 6.6 months, from April 10 to October 31. 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 33% on February 20.

Daily Chance of Precipitation

Daily Chance of Precipitation in CalistogawetwetdryJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Feb 2033%Feb 2033%Jul 190%Jul 190%Jan 129%Jan 129%Oct 3117%Oct 3117%Apr 1017%Apr 1017%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. Calistoga experiences extreme seasonal variation in monthly rainfall.

The rainy period of the year lasts for 8.0 months, from September 29 to May 30, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around February 16, with an average total accumulation of 5.6 inches.

The rainless period of the year lasts for 4.0 months, from May 30 to September 29. The least rain falls around July 29, 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 in Calistoga varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 28 minutes of daylight; the longest day is June 21, with 14 hours, 52 minutes of daylight.

Hours of Daylight and Twilight

Hours of Daylight and Twilight in CalistogaJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 6 minMar 2012 hr, 6 minMar 2014 hr, 52 minJun 2114 hr, 52 minJun 2112 hr, 9 minSep 2212 hr, 9 minSep 229 hr, 28 minDec 219 hr, 28 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 5:45 AM on June 14, and the latest sunrise is 1 hour, 54 minutes later at 7:39 AM on November 3. The earliest sunset is at 4:48 PM on December 5, and the latest sunset is 3 hours, 50 minutes later at 8:38 PM on June 28.

Daylight saving time (DST) is observed in Calistoga 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

Sunrise & Sunset with Twilight and Daylight Saving Time in CalistogaJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 145:45 AMJun 145:45 AM8:38 PMJun 288:38 PMJun 28Dec 54:48 PMDec 54:48 PM7:39 AMNov 37:39 AMNov 3Mar 11DSTMar 11DSTDSTNov 4DSTNov 4daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunriseSunset
The solar day over the course of the year 2018. 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 in Calistoga, 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

Humidity Comfort Levels in CalistogaJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Dec 280%Dec 280%Apr 240%Apr 240%drydrycomfortablecomfortable
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.

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 in Calistoga does not vary significantly over the course of the year, remaining within 0.5 miles per hour of 6.6 miles per hour throughout.

Average Wind Speed

Average Wind Speed in CalistogaJanFebMarAprMayJunJulAugSepOctNovDec0 mph1 mph2 mph3 mph4 mph5 mph6 mph7 mph8 mph9 mph10 mph11 mphMay 307.1 mphMay 307.1 mphOct 296.1 mphOct 296.1 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 in Calistoga varies throughout the year.

The wind is most often from the west for 7.3 months, from March 5 to October 14, with a peak percentage of 70% on July 31. The wind is most often from the north for 4.7 months, from October 14 to March 5, with a peak percentage of 51% on January 1.

Wind Direction

Wind Direction in CalistogaNWNJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%westnorthsoutheast
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).

Water Temperature

Calistoga 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 14 to October 30, with an average temperature above 56°F. The day of the year with the warmest water is September 23, with an average temperature of 57°F.

The time of year with cooler water lasts for 3.1 months, from March 26 to June 29, with an average temperature below 53°F. The day of the year with the coolest water is May 12, with an average temperature of 52°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 in Calistoga 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 Calistoga for general outdoor tourist activities is from late June to early September, with a peak score in the last week of July.

Tourism Score

Tourism Score in Calistogabest timeJanFebMarAprMayJunJulAugSepOctNovDec02468107.07.00.40.4 precipitationprecipitationcloudscloudstemperaturetemperaturetourism 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 Calistoga for hot-weather activities is from late June to late August, with a peak score in the third week of July.

Beach/Pool Score

Beach/Pool Score in Calistogabest timeJanFebMarAprMayJunJulAugSepOctNovDec02468103.33.30.00.0 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).

The growing season in Calistoga typically lasts for 8.3 months (255 days), from around March 11 to around November 20, rarely starting before February 4 or after April 18, and rarely ending before November 1 or after December 12.

Time Spent in Various Temperature Bands and the Growing Season

Time Spent in Various Temperature Bands and the Growing Season in Calistogagrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%50%Mar 1150%Mar 1150%Nov 2050%Nov 2090%Apr 1890%Apr 1890%Nov 190%Nov 110%Feb 410%Feb 410%Dec 1210%Dec 120%Jan 130%Jan 13Aug 3100%Aug 3100%very coldcoldcoolcomfortablewarmhot
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 Calistoga should appear around February 26, only rarely appearing before February 11 or after March 15.

Growing Degree Days

Growing Degree Days in CalistogaJanFebMarAprMayJunJulAugSepOctNovDec0°F500°F1,000°F1,500°F2,000°F2,500°F3,000°F3,500°FFeb 2690°FFeb 2690°FJun 11900°FJun 11900°FAug 11,800°FAug 11,800°FDec 313,287°FDec 313,287°F
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 3.5 months, from May 9 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 29, with an average of 8.5 kWh.

The darker period of the year lasts for 3.6 months, from November 3 to February 20, with an average daily incident shortwave energy per square meter below 3.3 kWh. The darkest day of the year is December 26, with an average of 2.0 kWh.

Average Daily Incident Shortwave Solar Energy

Average Daily Incident Shortwave Solar Energy in CalistogabrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh1 kWh2 kWh3 kWh4 kWh5 kWh6 kWh7 kWh8 kWh9 kWh10 kWhJun 298.5 kWhJun 298.5 kWhDec 262.0 kWhDec 262.0 kWhMay 97.2 kWhMay 97.2 kWhAug 257.2 kWhAug 257.2 kWhFeb 203.3 kWhFeb 203.3 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 Calistoga are 38.579 deg latitude, -122.580 deg longitude, and 751 ft elevation.

The topography within 2 miles of Calistoga contains very significant variations in elevation, with a maximum elevation change of 1,378 feet and an average elevation above sea level of 609 feet. Within 10 miles contains very significant variations in elevation (4,144 feet). Within 50 miles also contains extreme variations in elevation (6,102 feet).

The area within 2 miles of Calistoga is covered by cropland (40%), trees (26%), and shrubs (25%), within 10 miles by shrubs (43%) and trees (31%), and within 50 miles by shrubs (26%) and grassland (22%).

Data Sources

This report illustrates the typical weather in Calistoga, 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Calistoga.

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

The stations contributing to this reconstruction are: Sonoma County Airport (47%, 22 kilometers, west); Gnoss Field (19%, 48 kilometers, south); Napa County Airport (19%, 48 kilometers, southeast); and Nut Tree Airport (15%, 59 kilometers, east).

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.