This report describes the typical weather at the Essex County Airport (Caldwell, New Jersey, United States) weather station over the course of an average year. It is based on the historical records from 1987 to 2012. Earlier records are either unavailable or unreliable.
Caldwell, New Jersey has a humid continental climate with hot summers and no dry season. The area within 25 mi of this station is covered by forests (47%), built-up areas (39%), grasslands (6%), lakes and rivers (4%), and oceans and seas (2%).
Over the course of a year, the temperature typically varies from 23°F to 85°F and is rarely below 10°F or above 93°F.
The warm season lasts from May 29 to September 15 with an average daily high temperature above 76°F. The hottest day of the year is July 25, with an average high of 85°F and low of 67°F.
The cold season lasts from December 2 to March 8 with an average daily high temperature below 47°F. The coldest day of the year is January 24, with an average low of 23°F and high of 38°F.
The length of the day varies significantly over the course of the year. The shortest day is December 21 with 9:14 hours of daylight; the longest day is June 20 with 15:06 hours of daylight.
The earliest sunrise is at 5:24am on June 12 and the latest sunset is at 8:33pm on June 28. The latest sunrise is at 7:31am on November 3 and the earliest sunset is at 4:29pm on December 10.
Daylight savings time (DST) is observed in this location during 2012, starting in the spring on March 11 and ending in the fall on November 4.
The median cloud cover ranges from 29% (mostly clear) to 58% (partly cloudy). The sky is cloudiest on April 27 and clearest on July 24. The clearer part of the year begins around June 12. The cloudier part of the year begins around November 7.
On July 24, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 52% of the time, and overcast or mostly cloudy 31% of the time.
On April 27, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 46% of the time, and clear or mostly clear 39% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around April 27, occurring in 50% of days. Precipitation is least likely around October 10, occurring in 39% of days.
Over the entire year, the most common forms of precipitation are light rain, moderate rain, light snow, and thunderstorms.
Light rain is the most severe precipitation observed during 41% of those days with precipitation. It is most likely around April 26, when it is observed during 27% of all days.
Moderate rain is the most severe precipitation observed during 21% of those days with precipitation. It is most likely around October 13, when it is observed during 12% of all days.
Light snow is the most severe precipitation observed during 12% of those days with precipitation. It is most likely around February 1, when it is observed during 19% of all days.
Thunderstorms are the most severe precipitation observed during 11% of those days with precipitation. They are most likely around July 17, when it is observed during 14% of all days.
During the warm season, which lasts from May 29 to September 15, there is a 44% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light rain (40% of days with precipitation have at worst light rain), thunderstorms (24%), moderate rain (24%), and heavy rain (8%).
During the cold season, which lasts from December 2 to March 8, there is a 46% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light snow (32% of days with precipitation have at worst light snow), light rain (29%), moderate rain (14%), and moderate snow (11%).
The likelihood of snow falling is highest around February 5, occurring in 29% of days. The season in which it is relatively likely for snow to fall spans from December 2 to April 1.
Either snow rarely accumulates at this location or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 37% (comfortable) to 94% (very humid) over the course of the year, rarely dropping below 18% (dry) and reaching as high as 100% (very humid).
The air is driest around April 19, at which time the relative humidity drops below 46% (comfortable) three days out of four; it is most humid around September 17, exceeding 91% (very humid) three days out of four.
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a year, the dew point typically varies from 11°F (dry) to 68°F (muggy) and is rarely below -5°F (dry) or above 75°F (very muggy).
There are two periods in the year that are most comfortable: The first is between May 8 and June 25 and the second is between August 26 and October 15. The air feels neither too dry nor too muggy during these periods.
Over the course of the year typical wind speeds vary from 0 mph to 14 mph (calm to moderate breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 7 mph (light breeze) occurs around March 13, at which time the average daily maximum wind speed is 14 mph (moderate breeze).
The lowest average wind speed of 4 mph (light breeze) occurs around August 7, at which time the average daily maximum wind speed is 11 mph (gentle breeze).