Chelmsford (MA) Monthly Rainfall & Precipitation

This page shows both the average monthly rainfall and the number of rainy days in Chelmsford, Massachusetts, United States of America. These values are calculated using 30 years of data (1990–2020) to ensure accuracy. Now, let's break down all the details for a clearer picture.

Chelmsford experiences significant rain/snowfall throughout the year, averaging 1278 mm (50 in) of precipitation annually.

Monthly Precipitation Levels

The average number of days each month with precipitation (> 0.2 mm (0.01 in))

The wettest period in Chelmsford occurs in October, which receives around 129 mm (5.1 in) of precipitation. During the driest month, January, Chelmsford experiences moderate snowfall, totaling approximately 88 mm (3.5 in). The consistent precipitation levels throughout the year contribute to a relatively stable climate.

October, the wettest month, has a maximum daytime temperature of 17°C (63°F). The city receives 207 hours of sunshine in this period. During the driest month January you can expect a temperature of 2°C (36°F). For more detailed insights into the city's temperatures, visit our Chelmsford Temperature page.

Chelmsford's average annual precipitation is 1278 mm (50 in). Let's compare this to some popular worldwide tourist destinations:

In Barcelona, Spain, the average annual precipitation is 644 mm (25 in), evenly distributed across the year with no extreme wet or dry seasons.

In Shanghai, China, the annual average precipitation is 1347 mm (53 in), with a humid subtropical climate.

Adelaide, Australia, enjoys 511 mm (20 in) of annual precipitation, with dry summers and wet winters.

Singapore, situated near the equator, gets 2581 mm (102 in) of rainfall annually, with no distinct dry season and consistent monthly precipitation.

Precipitation amounts are measured using specific gauges installed at weather stations, collecting both rain and snow and any other type of precipitation. Rainfall is measured directly in millimeters, while that from snow and ice is obtained by melting it. Automated systems often incorporate heaters to make this easier.

Information from these stations is transmitted via Wi-Fi, satellite, GPS, or telephone connections to central monitoring networks. This information is immediately updated and integrated into weather models and forecasts.

The proximity of a location to a large body of water can significantly affect its rainfall patterns:

• Ocean Influence: Coastal regions typically receive more rainfall due to the presence of moisture-laden winds from the ocean. These regions tend to have more humid climates and experience more frequent precipitation, especially in winter.
• Continental Climates: Areas further from the sea, such as inland or continental regions, experience less frequent rainfall and more extreme seasonal variations in precipitation.

• "Ginger" was the longest-lasting Atlantic tropical storm, which spun around the open ocean for 28 days in 1971.
• The world's largest snowflake was recorded in the Guinness Book of Records, at 38 cm (15 inches) wide and 20 cm (7.9 inches) thick. The snowflake fell at Fort Keogh, Montana, USA, on 28 January 1887.
• The greatest snowfall recorded was on Mt. Rainier, Washington State, USA, over 31.5 meters (103 feet) fell during the winter of 1972.

For more detailed information about Chelmsford (MA)'s weather, including sunshine hours, humidity levels, and temperature data, visit our Chelmsford (MA) Climate page.