Geography of Hillsborough County, New Hampshire

Hillsborough County, located in the southern part of the state of New Hampshire, is a region characterized by its diverse geography, including rolling hills, fertile valleys, meandering rivers, and picturesque lakes. From the scenic landscapes of the Monadnock Region to the urban centers of Manchester and Nashua, the county’s geography plays a significant role in shaping its environment, climate, and cultural heritage.

Topography and Landscapes:

According to Aparentingblog, Hillsborough County’s topography is varied, encompassing both rural countryside and urban centers. The county is situated within the Merrimack Valley and Monadnock Region of New Hampshire, known for its rolling hills, fertile plains, and scenic beauty.

The western part of Hillsborough County is dominated by the Monadnock Region, named after Mount Monadnock, one of the most prominent mountains in the region. Mount Monadnock, known for its distinctive bald summit and panoramic views, is a popular destination for hikers, climbers, and outdoor enthusiasts. The surrounding landscape is characterized by wooded hills, meandering streams, and picturesque villages, offering opportunities for outdoor recreation and scenic drives.

To the east of the Monadnock Region lies the Merrimack Valley, a fertile lowland area that stretches from central New Hampshire to the coast. The valley is home to the Merrimack River, one of the longest rivers in New England, which flows from north to south through the heart of the county. The Merrimack River valley is known for its rich agricultural soils, historic mill towns, and vibrant cultural scene.

In addition to its natural landscapes, Hillsborough County is home to several urban centers, including the city of Manchester, the largest city in the state, and the city of Nashua, the second-largest city. These urban areas serve as economic and cultural hubs, with diverse populations, thriving businesses, and cultural attractions.


Hillsborough County experiences a humid continental climate, characterized by four distinct seasons with varying temperatures and precipitation levels. Summers are typically warm and humid, with average daytime temperatures ranging from the 70s to the 80s Fahrenheit. Thunderstorms are common during the summer months, bringing heavy rain, lightning, and occasional severe weather.

Winters in Hillsborough County are cold and snowy, with average daytime temperatures ranging from the 20s to the 30s Fahrenheit. Snowfall is common during the winter months, with accumulations varying depending on elevation and proximity to the mountains. Higher elevations in the Monadnock Region may receive more snow than lower-lying areas in the valley.

Spring and autumn are transitional seasons, characterized by mild temperatures and fluctuating weather patterns. These seasons are popular times for outdoor activities such as hiking, biking, and leaf-peeping, as the landscape comes alive with blooming flowers and changing foliage.

Rivers and Lakes:

The Merrimack River is the most significant waterway in Hillsborough County, flowing from north to south through the central part of the region. The river provides habitat for fish, birds, and other wildlife, as well as opportunities for fishing, boating, and kayaking. Several smaller tributaries flow into the Merrimack River within the county, including the Souhegan River and the Piscataquog River, contributing to its drainage network and providing additional habitat for aquatic species.

While natural lakes are scarce in Hillsborough County, there are several reservoirs and impoundments created for water supply, flood control, and recreational purposes. Notable lakes include Lake Massabesic, located to the east of Manchester, and Everett Lake, located to the west of Concord. These lakes offer opportunities for fishing, boating, and picnicking, as well as habitat for waterfowl and other wildlife.

Natural Resources:

Hillsborough County’s geography is rich in natural resources, including fertile soils, forests, and waterways. Agriculture has historically been an important part of the county’s economy, with crops such as corn, apples, pumpkins, and dairy products grown in the fertile valleys and fields. The county’s farms and orchards contribute to the local food supply and support agritourism activities such as pick-your-own farms and farmers’ markets.

The county’s forests are composed primarily of hardwoods such as oak, maple, and birch, providing habitat for wildlife, recreational opportunities, and timber resources. Hillsborough County’s parks and open spaces offer residents and visitors a chance to explore and enjoy the natural beauty of the region, with hiking trails, picnic areas, and scenic overlooks.

Water resources are also important natural assets in Hillsborough County, supporting a variety of ecosystems and human activities. The Merrimack River and its tributaries provide habitat for fish, birds, and other wildlife, as well as opportunities for fishing, boating, and kayaking. The county’s lakes and reservoirs help ensure a reliable supply of drinking water for residents and support recreational activities such as swimming and paddling.


In summary, Hillsborough County, New Hampshire, offers a diverse and picturesque geography shaped by its topography, climate, rivers, and lakes. From the rolling hills and fertile plains to the bustling urban centers, the county’s landscapes provide a rich tapestry of ecosystems and habitats.

The region’s humid continental climate supports a wide range of plant and animal species, while its rivers and lakes offer opportunities for recreation and relaxation. As Hillsborough County continues to grow and develop, its geography will remain a fundamental aspect of its identity, shaping the lives and experiences of its residents and visitors for generations to come. Preserving the region’s natural beauty and ecological diversity will be essential to ensuring a sustainable future for this unique and remarkable corner of New Hampshire.