Merrillville (IN) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit Merrillville.
Climate overview of Merrillville
Merrillville, Indiana, United States of America, experiences significant temperature variation throughout the year. Summers bring daytime highs of 29°C (84°F) in July, while winters cool to 0°C (32°F) in January.
Rain/snowfall is high, totalling around 1096 mm (43 in) per year. August is the wettest month and November the driest. The city also experiences warm summers and very cold winters. The most sunshine falls in July, with an average of 10.6 hours of daily sunshine.
Merrillville Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in Merrillville - and find the best time to visit.
Monthly Temperature in Merrillville
Depending on the time of the year, temperatures range from comfortable to very cold in Merrillville. Average maximum daytime temperatures range from a comfortable 29°C (84°F) in July, the warmest time of the year, to a very cold 0°C (32°F) during cooler months like January.
At night, you can expect temperatures ranging from 18°C (64°F) in July to around -9°C (16°F) during January.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in Merrillville
Merrillville has a relatively rain/snowy climate with high precipitation levels, averaging 1096 mm (43 in) of rain/snowfall annually. Significant seasonal changes in precipitation occur throughout the year. In the wettest month, August it receives high rainfall, averaging 146 mm (5.7 in) of precipitation, recorded across 11 rainy days. In contrast, the driest month November brings less rainfall, with 55 mm (2.2 in) over 9 rainy days. For more details, please visit our Merrillville Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in Merrillville
Seasonal changes in sunshine hours are quite dramatic in Merrillville. While July receives considerable daily sunshine with up to 10.6 hours, December marks the darkest time of the year, where sunshine is scarce with only 3.6 hours of sunlight per day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Humidity in Merrillville by Month
The relative humidity is high throughout the year in Merrillville.
The city experiences its highest humidity in December, reaching 76%. In May, the humidity drops to its lowest level at 64%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Best Time to Visit Merrillville
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: May, June, July, August and September
- Warmest weather: July and August
- Most sunshine: June and July
- Seasonal pattern: Warm summers and very cold winters
- Coldest conditions: January, with freezing nights around -9°C (16°F).
Frequently asked questions about the climate in Merrillville
What is the best time to visit Merrillville?
May, June, July, August and September typically offer the most optimal weather in Merrillville. In contrast, January, February, March, November and December tend to have less optimal conditions. Merrillville has warm summers and very cold winters.
What temperatures can I expect in Merrillville?
Daytime highs range from 0°C (32°F) in January to 29°C (84°F) in July. Nighttime lows range from -9°C (16°F) to 18°C (64°F). Temperatures vary considerably through the year.
How much rain does Merrillville get?
Annual rainfall is around 1096 mm (43 in). August is the wettest month with 146 mm (5.7 in), while November is the driest with 55 mm (2.2 in).
How sunny is Merrillville?
Merrillville receives around 2,509 hours of sunshine per year. July is the sunniest month with 319 hours, while December is the cloudiest with just 107 hours. Overall, Merrillville enjoys abundant sunshine.
Merrillville 3-Day Forecast
Merrillville (IN) 3-Day Forecast
Merrillville on the map
Merrillville is highlighted - select any city to see its climate.
Popular this month
Where to go in July - average daytime high across popular destinations.
Bucket list
Need travel inspiration? Check out our bucket list articles and be inspired.
Yosemite National Park is definitely worth a visit
Vast forests, blue lakes, towering sequoias, and majestic waterfalls hint at the beauty of Yosemite National Park—a true natural masterpiece.
The 10 most alternative cities in the United States
Discover the top 10 fun and alternative U.S. cities rich in art, culture, and adventure. From Portland's hippy charm to Sedona's stunning landscapes.
Sedona: Explore Majestic Red Rock Landscapes
A picturesque artists' town surrounded by red rocks and known for its spirituality, vortex energy, and stunning hikes like Cathedral Rock.
10 most idyllic villages to visit in the United States
Discover 10 idyllic villages in the USA, from California to Vermont. Explore their unique charm, rich history, stunning nature, and vibrant arts scenes.