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Average Weather in Collinsville Connecticut, United States

In Collinsville, the summers are warm and wet, the winters are freezing, and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 19°F to 82°F and is rarely below 4°F or above 90°F.

Climate Summary

very coldcoldcoolwarmcoolcoldvery coldJanFebMarAprMayJunJulAugSepOctNovDec65%65%45%45%clearovercastprecipitation: 3.9 inprecipitation: 3.9 in2.7 in2.7 inmuggy: 38%muggy: 38%0%0%drydrytourism score: 6.6tourism score: 6.60.00.0
Click on each chart for more information.

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

Temperature

The warm season lasts for 3.6 months, from May 29 to September 16, with an average daily high temperature above 73°F. The hottest day of the year is July 21, with an average high of 82°F and low of 64°F.

The cold season lasts for 3.3 months, from December 2 to March 11, with an average daily high temperature below 43°F. The coldest day of the year is January 30, with an average low of 19°F and high of 34°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 CollinsvilleJanFebMarAprMayJunJulAugSepOctNovDec12 AM4 AM8 AM12 PM4 PM8 PM12 AMfreezingvery coldvery coldcoldcoldcoolcomfortablewarmcomfortablefreezingfreezing
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.

Grazhdanskoye, Russia (5,291 miles away); Tegh, Armenia (5,659 miles); and Soleh Bon, Iran (6,072 miles) are the far-away foreign places with temperatures most similar to Collinsville (view comparison).

Clouds

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

The clearer part of the year in Collinsville begins around June 25 and lasts for 4.5 months, ending around November 10. On September 6, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 65% of the time, and overcast or mostly cloudy 35% of the time.

The cloudier part of the year begins around November 10 and lasts for 7.5 months, ending around June 25. On January 3, the cloudiest day of the year, the sky is overcast or mostly cloudy 55% of the time, and clear, mostly clear, or partly cloudy 45% of the time.

Cloud Cover Categories

Cloud Cover Categories in CollinsvilleclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Sep 665%Sep 665%Jan 345%Jan 345%Jun 2555%Jun 2555%Nov 1055%Nov 1055%clearmostly clearpartly cloudymostly cloudyovercast
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 in Collinsville varies throughout the year.

The wetter season lasts 3.5 months, from May 4 to August 21, with a greater than 29% chance of a given day being a wet day. The chance of a wet day peaks at 37% on May 31.

The drier season lasts 8.5 months, from August 21 to May 4. The smallest chance of a wet day is 22% on January 29.

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 in Collinsville changes throughout the year.

Rain alone is the most common for 12 months, from January 21 to January 7. The highest chance of a day with rain alone is 37% on May 31.

Snow alone is the most common for 2.0 weeks, from January 7 to January 21. The highest chance of a day with snow alone is 10% on January 9.

Daily Chance of Precipitation

Daily Chance of Precipitation in CollinsvillerainJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%May 3137%May 3137%Jan 2922%Jan 2922%Jan 126%Jan 126%Aug 2129%Aug 2129%snowrainmixed
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. Collinsville experiences significant seasonal variation in monthly rainfall.

Rain falls throughout the year in Collinsville. The most rain falls during the 31 days centered around October 3, with an average total accumulation of 3.9 inches.

The least rain falls around January 24, with an average total accumulation of 1.5 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.

Snowfall

We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Collinsville experiences significant seasonal variation in monthly liquid-equivalent snowfall.

The snowy period of the year lasts for 5.6 months, from October 29 to April 16, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around January 24, with an average total liquid-equivalent accumulation of 1.2 inches.

The snowless period of the year lasts for 6.4 months, from April 16 to October 29. The least snow falls around July 21, with an average total liquid-equivalent accumulation of 0.0 inches.

Average Liquid-Equivalent Monthly Snowfall

Average Liquid-Equivalent Monthly Snowfall in CollinsvillesnowsnowJanFebMarAprMayJunJulAugSepOctNovDec0.0 in0.5 in1.0 in1.5 in2.0 in2.5 in3.0 in3.5 in4.0 inJan 241.2 inJan 241.2 inJul 210.0 inJul 210.0 inOct 290.1 inOct 290.1 inApr 160.1 inApr 160.1 in
The average liquid-equivalent snowfall (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 rainfall.

Sun

The length of the day in Collinsville varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 8 minutes of daylight; the longest day is June 21, with 15 hours, 13 minutes of daylight.

Hours of Daylight and Twilight

Hours of Daylight and Twilight in CollinsvilleJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 7 minMar 2012 hr, 7 minMar 2015 hr, 13 minJun 2115 hr, 13 minJun 2112 hr, 9 minSep 2212 hr, 9 minSep 229 hr, 8 minDec 219 hr, 8 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 5:16 AM on June 14, and the latest sunrise is 2 hours, 12 minutes later at 7:27 AM on November 4. The earliest sunset is at 4:20 PM on December 8, and the latest sunset is 4 hours, 10 minutes later at 8:30 PM on June 26.

Daylight saving time (DST) is observed in Collinsville 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 in CollinsvilleJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 145:16 AMJun 145:16 AM8:30 PMJun 268:30 PMJun 26Dec 84:20 PMDec 84:20 PM7:27 AMNov 47:27 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.

Collinsville experiences significant seasonal variation in the perceived humidity.

The muggier period of the year lasts for 3.4 months, from June 7 to September 21, during which time the comfort level is muggy, oppressive, or miserable at least 10% of the time. The muggiest day of the year is July 30, with muggy conditions 38% of the time.

The least muggy day of the year is February 21, when muggy conditions are essentially unheard of.

Humidity Comfort Levels

Humidity Comfort Levels in CollinsvillemuggyJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Feb 210%Feb 210%Jul 3038%Jul 3038%Jun 710%Jun 710%Sep 2110%Sep 2110%muggymuggydrydryhumidhumidoppressiveoppressivecomfortablecomfortable
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 in Collinsville experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 5.4 months, from November 12 to April 24, with average wind speeds of more than 5.1 miles per hour. The windiest day of the year is February 26, with an average hourly wind speed of 6.7 miles per hour.

The calmer time of year lasts for 6.6 months, from April 24 to November 12. The calmest day of the year is August 1, with an average hourly wind speed of 3.6 miles per hour.

Average Wind Speed

Average Wind Speed in CollinsvillewindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph1 mph2 mph3 mph4 mph5 mph6 mph7 mph8 mph9 mph10 mph11 mphFeb 266.7 mphFeb 266.7 mphAug 13.6 mphAug 13.6 mphNov 125.1 mphNov 125.1 mphApr 245.1 mphApr 245.1 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 Collinsville varies throughout the year.

The wind is most often from the south for 3.0 days, from August 20 to August 23 and for 1.0 months, from August 29 to September 29, with a peak percentage of 31% on August 20. The wind is most often from the west for 6.0 days, from August 23 to August 29 and for 11 months, from September 29 to August 20, with a peak percentage of 31% on August 23.

Wind Direction

Wind Direction in CollinsvilleWSWJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%westsouthnortheast
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

Collinsville 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 significant seasonal variation over the course of the year.

The time of year with warmer water lasts for 3.6 months, from June 24 to October 11, with an average temperature above 64°F. The day of the year with the warmest water is August 12, with an average temperature of 71°F.

The time of year with cooler water lasts for 3.5 months, from December 31 to April 14, with an average temperature below 43°F. The day of the year with the coolest water is February 21, with an average temperature of 36°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 Collinsville 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 Collinsville for general outdoor tourist activities is from mid June to mid September, with a peak score in the third week of August.

Tourism Score

Tourism Score in Collinsvillebest timeJanFebMarAprMayJunJulAugSepOctNovDec02468106.66.60.00.0 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 Collinsville for hot-weather activities is from early July to mid August, with a peak score in the last week of July.

Beach/Pool Score

Beach/Pool Score in Collinsvillebest timeJanFebMarAprMayJunJulAugSepOctNovDec02468105.35.30.00.0precipitationprecipitationcloudscloudstemperaturetemperaturebeach/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 Collinsville typically lasts for 5.8 months (176 days), from around April 23 to around October 17, rarely starting before April 6 or after May 16, and rarely ending before September 29 or after November 4.

Time Spent in Various Temperature Bands and the Growing Season

Time Spent in Various Temperature Bands and the Growing Season in Collinsvillegrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Apr 2350%Apr 2350%Oct 1750%Oct 1750%May 1690%May 1690%Sep 2990%Sep 2990%Apr 610%Apr 610%Nov 410%Nov 410%0%Feb 110%Feb 11Jul 26100%Jul 26100%freezingvery coldcoolcomfortablewarmcoldhot
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.

Based on growing degree days alone, the first spring blooms in Collinsville should appear around April 22, only rarely appearing before April 8 or after May 3.

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 3.6 months, from May 2 to August 21, with an average daily incident shortwave energy per square meter above 5.8 kWh. The brightest day of the year is June 30, with an average of 6.9 kWh.

The darker period of the year lasts for 3.2 months, from November 4 to February 11, with an average daily incident shortwave energy per square meter below 2.7 kWh. The darkest day of the year is December 23, with an average of 1.6 kWh.

Average Daily Incident Shortwave Solar Energy

Average Daily Incident Shortwave Solar Energy in CollinsvillebrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh1 kWh2 kWh3 kWh4 kWh5 kWh6 kWh7 kWh8 kWh9 kWhJun 306.9 kWhJun 306.9 kWhDec 231.6 kWhDec 231.6 kWhMay 25.8 kWhMay 25.8 kWhAug 215.8 kWhAug 215.8 kWhNov 42.7 kWhNov 42.7 kWhFeb 112.7 kWhFeb 112.7 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 Collinsville are 41.813 deg latitude, -72.920 deg longitude, and 482 ft elevation.

The topography within 2 miles of Collinsville contains significant variations in elevation, with a maximum elevation change of 538 feet and an average elevation above sea level of 473 feet. Within 10 miles contains significant variations in elevation (1,158 feet). Within 50 miles contains very significant variations in elevation (2,605 feet).

The area within 2 miles of Collinsville is covered by trees (68%), water (16%), and artificial surfaces (15%), within 10 miles by trees (79%) and artificial surfaces (18%), and within 50 miles by trees (76%) and artificial surfaces (12%).

Data Sources

This report illustrates the typical weather in Collinsville, 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 Collinsville.

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

The stations contributing to this reconstruction are: Hartford-Brainard Airport (30%, 24 kilometers, east); Bradley International Airport (33%, 24 kilometers, northeast); Meriden Markham Municipal Airport (20%, 35 kilometers, south); and Waterbury-Oxford Airport (17%, 41 kilometers, southwest).

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.