Climate and Average Weather Year Round in Norwalk United States

In Norwalk, the summers are warm; the winters are freezing, snowy, and windy; and it is partly cloudy year round. Over the course of the year, the temperature typically varies from 21°F to 82°F and is rarely below 5°F or above 89°F.

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

The warm season lasts for 3.8 months, from May 26 to September 19, with an average daily high temperature above 72°F. The hottest month of the year in Norwalk is July, with an average high of 81°F and low of 66°F.

The cold season lasts for 3.2 months, from December 2 to March 7, with an average daily high temperature below 43°F. The coldest month of the year in Norwalk is January, with an average low of 22°F and high of 34°F.

In Norwalk, 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 Norwalk begins around May 31 and lasts for 5.3 months, ending around November 8.

The clearest month of the year in Norwalk is August, during which on average the sky is clear, mostly clear, or partly cloudy 68% of the time.

The cloudier part of the year begins around November 8 and lasts for 6.7 months, ending around May 31.

The cloudiest month of the year in Norwalk is January, during which on average the sky is overcast or mostly cloudy 66% 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 Norwalk varies throughout the year.

The wetter season lasts 6.0 months, from March 23 to September 23, with a greater than 28% chance of a given day being a wet day. The month with the most wet days in Norwalk is June, with an average of 11.2 days with at least 0.04 inches of precipitation.

The drier season lasts 6.0 months, from September 23 to March 23. The month with the fewest wet days in Norwalk is February, with an average of 5.6 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 Norwalk is June, with an average of 11.2 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 39% on June 14.

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. Norwalk experiences significant seasonal variation in monthly rainfall.

Rain falls throughout the year in Norwalk. The month with the most rain in Norwalk is June, with an average rainfall of 3.1 inches.

The month with the least rain in Norwalk is February, with an average rainfall of 1.1 inches.

Snowfall

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

The snowy period of the year lasts for 4.1 months, from November 30 to April 1, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in Norwalk is February, with an average snowfall of 3.5 inches.

The snowless period of the year lasts for 7.9 months, from April 1 to November 30. The least snow falls around August 2, with an average total accumulation of 0.0 inches.

The length of the day in Norwalk varies significantly over the course of the year. In 2024, the shortest day is December 21, with 9 hours, 12 minutes of daylight; the longest day is June 20, with 15 hours, 9 minutes of daylight.

The earliest sunrise is at 5:56 AM on June 14, and the latest sunrise is 2 hours, 7 minutes later at 8:03 AM on November 2. The earliest sunset is at 5:01 PM on December 7, and the latest sunset is 4 hours, 6 minutes later at 9:07 PM on June 26.

Daylight saving time (DST) is observed in Norwalk 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.

Norwalk experiences significant seasonal variation in the perceived humidity.

The muggier period of the year lasts for 3.7 months, from May 29 to September 18, during which time the comfort level is muggy, oppressive, or miserable at least 10% of the time. The month with the most muggy days in Norwalk is July, with 11.6 days that are muggy or worse.

The least muggy day of the year is February 10, when muggy conditions are essentially unheard of.

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 Norwalk experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 6.8 months, from October 6 to May 1, with average wind speeds of more than 10.9 miles per hour. The windiest month of the year in Norwalk is January, with an average hourly wind speed of 13.8 miles per hour.

The calmer time of year lasts for 5.2 months, from May 1 to October 6. The calmest month of the year in Norwalk is August, with an average hourly wind speed of 8.0 miles per hour.

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

The wind is most often from the south for 5.0 days, from May 21 to May 26 and for 1.4 months, from August 27 to October 7, with a peak percentage of 33% on October 2. The wind is most often from the west for 3.0 months, from May 26 to August 27 and for 7.5 months, from October 7 to May 21, with a peak percentage of 39% on July 19.

Norwalk 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 3.3 months, from June 19 to September 27, with an average temperature above 65°F. The month of the year in Norwalk with the warmest water is August, with an average temperature of 71°F.

The time of year with cooler water lasts for 4.0 months, from December 13 to April 14, with an average temperature below 43°F. The month of the year in Norwalk with the coolest water is February, with an average temperature of 36°F.

To characterize how pleasant the weather is in Norwalk 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 Norwalk for general outdoor tourist activities is from mid June to mid September, with a peak score in the third 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 Norwalk for hot-weather activities is from late June to mid August, with a peak score in the third week of July.

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).

The growing season in Norwalk typically lasts for 6.7 months (205 days), from around April 14 to around November 5, rarely starting before March 29 or after May 1, and rarely ending before October 19 or after November 22.

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 Norwalk should appear around April 12, only rarely appearing before March 28 or after April 25.

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 3.8 months, from April 30 to August 24, with an average daily incident shortwave energy per square meter above 5.8 kWh. The brightest month of the year in Norwalk is June, with an average of 6.8 kWh.

The darker period of the year lasts for 3.4 months, from November 3 to February 13, with an average daily incident shortwave energy per square meter below 2.6 kWh. The darkest month of the year in Norwalk is December, with an average of 1.6 kWh.

For the purposes of this report, the geographical coordinates of Norwalk are 41.243 deg latitude, -82.616 deg longitude, and 715 ft elevation.

The topography within 2 miles of Norwalk contains only modest variations in elevation, with a maximum elevation change of 180 feet and an average elevation above sea level of 717 feet. Within 10 miles also contains only modest variations in elevation (453 feet). Within 50 miles contains only modest variations in elevation (994 feet).

The area within 2 miles of Norwalk is covered by artificial surfaces (56%) and cropland (41%), within 10 miles by cropland (91%), and within 50 miles by cropland (58%) and water (27%).