Average Weather in Northampton Massachusetts, United States
In Northampton, 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 17°F to 83°F and is rarely below 0°F or above 91°F.
Based on the tourism score, the best time of year to visit Northampton for warm-weather activities is from mid June to mid September.
The warm season lasts for 3.6 months, from May 28 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 83°F and low of 63°F.
The cold season lasts for 3.3 months, from December 1 to March 12, with an average daily high temperature below 43°F. The coldest day of the year is January 29, with an average low of 17°F and high of 34°F.
Average High and Low Temperature
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
In Northampton, 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 Northampton begins around June 25 and lasts for 4.2 months, ending around November 1. On September 2, 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 1 and lasts for 7.8 months, ending around June 25. On February 28, 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
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Northampton varies throughout the year.
The wetter season lasts 4.3 months, from April 13 to August 22, 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 30.
The drier season lasts 7.7 months, from August 22 to April 13. The smallest chance of a wet day is 21% 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 throughout the year is rain alone, with a peak probability of 37% on May 30.
Daily Chance of Precipitation
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. Northampton experiences significant seasonal variation in monthly rainfall.
Rain falls throughout the year in Northampton. The most rain falls during the 31 days centered around October 4, with an average total accumulation of 4.0 inches.
The least rain falls around January 23, with an average total accumulation of 1.5 inches.
Average Monthly Rainfall
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. Northampton experiences significant seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 5.3 months, from November 3 to April 13, 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 26, with an average total liquid-equivalent accumulation of 1.1 inches.
The snowless period of the year lasts for 6.7 months, from April 13 to November 3. The least snow falls around July 22, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Northampton varies significantly over the course of the year. In 2018, the shortest day is December 21, with 9 hours, 5 minutes of daylight; the longest day is June 21, with 15 hours, 17 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:13 AM on June 15, and the latest sunrise is 2 hours, 13 minutes later at 7:26 AM on November 3. The earliest sunset is at 4:17 PM on December 7, and the latest sunset is 4 hours, 13 minutes later at 8:31 PM on June 27.
Daylight saving time (DST) is observed in Northampton 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
Northampton experiences significant seasonal variation in the perceived humidity.
The muggier period of the year lasts for 3.4 months, from June 7 to September 20, during which time the comfort level is muggy, oppressive, or miserable at least 9% of the time. The muggiest day of the year is July 30, with muggy conditions 35% of the time.
The least muggy day of the year is February 23, when muggy conditions are essentially unheard of.
Humidity Comfort Levels
The average hourly wind speed in Northampton experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 5.3 months, from November 17 to April 26, 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 6.6 miles per hour.
The calmer time of year lasts for 6.7 months, from April 26 to November 17. The calmest day of the year is August 7, with an average hourly wind speed of 3.5 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Northampton is from the west throughout the year.
Best Time of Year to Visit
To characterize how pleasant the weather is in Northampton 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 Northampton 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 Northampton for hot-weather activities is from early July to mid August, with a peak score in the last week of July.
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.
The growing season in Northampton typically lasts for 5.4 months (163 days), from around April 29 to around October 10, rarely starting before April 12 or after May 18, and rarely ending before September 23 or after October 26.
Time Spent in Various Temperature Bands and the Growing Season
Based on growing degree days alone, the first spring blooms in Northampton should appear around April 21, only rarely appearing before April 8 or after May 1.
Growing Degree Days
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 3 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 3.3 months, from November 2 to February 11, with an average daily incident shortwave energy per square meter below 2.6 kWh. The darkest day of the year is December 23, with an average of 1.6 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Northampton are 42.325 deg latitude, -72.641 deg longitude, and 148 ft elevation.
The topography within 2 miles of Northampton contains only modest variations in elevation, with a maximum elevation change of 230 feet and an average elevation above sea level of 168 feet. Within 10 miles contains only modest variations in elevation (1,490 feet). Within 50 miles contains very significant variations in elevation (3,579 feet).
The area within 2 miles of Northampton is covered by artificial surfaces (63%) and trees (24%), within 10 miles by trees (68%) and artificial surfaces (20%), and within 50 miles by trees (85%).
This report illustrates the typical weather in Northampton, 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 5 weather stations near enough to contribute to our estimation of the temperature and dew point in Northampton.
For each station, the records are corrected for the elevation difference between that station and Northampton 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 Northampton is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Northampton and a given station.
The stations contributing to this reconstruction are: Westover Air Reserve Base / Metropolitan Airport (43%, 17 kilometers, southeast); Barnes Municipal Airport (33%, 20 kilometers, south); Orange Municipal Airport (11%, 40 kilometers, northeast); Pittsfield Municipal Airport (6%, 54 kilometers, west); and Harriman and West Airport (6%, 60 kilometers, northwest).
Time zones for aiports and weather stations are provided by AskGeo.com .