Climate of Portland, Maine

Portland, Maine, located in the northeastern United States, experiences a diverse climate with four distinct seasons. The city is known for its maritime influence, cool summers, cold winters, and frequent precipitation throughout the year. Portland’s climate is significantly shaped by its coastal location along the Gulf of Maine, which moderates temperatures and influences weather patterns. In this comprehensive exploration of Portland’s climate, we will delve into the city’s annual weather patterns, seasonal variations, and notable climatic features.

Geographic Location and Influences:

According to citiesplustowns, Portland is situated in the southern part of Maine along the coast of the Gulf of Maine, an arm of the Atlantic Ocean. The city’s climate is significantly influenced by its geographical features, which include its coastal location and proximity to the Gulf Stream. Several key factors contribute to Portland’s climate:

  1. Maritime Influence: Portland’s coastal position exerts a strong maritime influence on its climate. The relatively stable temperature of the ocean waters helps moderate the city’s temperature fluctuations throughout the year.
  2. Gulf Stream: The nearby Gulf Stream, a warm ocean current, contributes to milder winter temperatures and affects weather patterns in the region.

Seasonal Overview:

Portland experiences four distinct seasons, each with its own unique weather patterns. Here is an overview of the seasons in Portland:

  • Spring (March – May): Spring in Portland is a transitional season marked by warming temperatures and the gradual return of greenery. Daytime highs typically range from the 40s to 60s Fahrenheit (4-20°C). Spring can bring rain showers, and occasional snowfall is possible in March.
  • Summer (June – August): Summers in Portland are relatively cool for a coastal city. Daytime temperatures typically range from the 70s to low 80s Fahrenheit (21-28°C). Humidity levels are moderate, and the city experiences occasional afternoon showers.
  • Fall (September – November): Fall is a favorite season for many in Portland. Daytime highs generally range from the 60s to low 70s Fahrenheit (16-24°C). Nights become cooler, with temperatures in the 40s and 50s°F (4-15°C). Fall is typically dry and marked by colorful foliage.
  • Winter (December – February): Winters in Portland are cold, but not extremely frigid. Daytime highs typically range from the 30s to low 40s Fahrenheit (2-7°C). Nights are colder, often dropping below freezing, with temperatures in the 20s and 30s°F (-6 to 4°C). Snowfall is common, and the city experiences distinct winter storms.

Temperature Trends:

Portland’s climate is characterized by milder temperatures, especially during the winter, compared to other locations at similar latitudes. Here’s a closer look at temperature trends in the city:

  • Average Annual Temperature: Portland has an average annual temperature of around 47°F (8°C), which reflects the moderating influence of the nearby ocean.
  • Summer Temperatures: Summers in Portland are relatively cool for a coastal city. Daytime highs typically range from the 70s to low 80s Fahrenheit (21-28°C). Nights are cooler, with temperatures in the 50s to low 60s°F (10-20°C).
  • Winter Temperatures: Winters in Portland are cold but not extreme, with daytime highs typically ranging from the 30s to low 40s Fahrenheit (2-7°C). Nights are significantly colder, often dropping into the 20s and 30s°F (-6 to 4°C).
  • Spring and Fall Temperatures: Spring and fall offer milder conditions. Daytime highs generally range from the 40s to 70s Fahrenheit (4-24°C). Nights are cooler, with temperatures in the 30s to 50s°F (1-15°C).


Portland receives a relatively even distribution of precipitation throughout the year. The city has an annual average of approximately 45 inches (1,143 mm) of precipitation. Here’s how precipitation is distributed throughout the year:

  • Spring Showers: Spring brings occasional rain showers to Portland, along with the possibility of snowfall in March. These showers contribute to the renewal of plant life.
  • Summer Showers: Summers in Portland are characterized by occasional afternoon showers, but the city generally experiences less rainfall during this season.
  • Fall Rainfall: Fall is typically dry in Portland, offering pleasant weather for enjoying the vibrant foliage.
  • Winter Snowfall: Portland experiences snowfall during the winter months, with frequent winter storms. The city typically receives around 61 inches of snow annually, and snowfall is common in the region.

Climatic Features:

  • Maritime Influence: The proximity to the Gulf of Maine moderates Portland’s temperatures, making winters milder and summers cooler compared to more inland locations at similar latitudes.
  • Coastal Storms: Portland is susceptible to coastal storms, especially during the winter, which can bring heavy snowfall and strong winds. These storms are known as Nor’easters.
  • Outdoor Activities: Portland’s mild summers and vibrant fall foliage make it an excellent destination for outdoor enthusiasts, offering opportunities for hiking, biking, and exploring the city’s beautiful coastal landscapes.


Portland, Maine, experiences a four-season climate with distinct temperature variations throughout the year. The city’s coastal location and proximity to the Gulf Stream contribute to its relatively mild climate, with cooler summers and milder winters compared to more inland areas at similar latitudes. While Portland’s climate presents seasonal challenges, such as winter storms and occasional coastal storms, it also provides a rich natural environment and outdoor activities for residents and visitors to enjoy year-round. The climate is an integral part of Portland’s identity, offering a unique and refreshing environment to explore and experience.

Map of Portland, Maine