Merrillville Weather in September

During September, Merrillville experiences high daytime temperatures of 25°C (77°F) and cooler nights around 13°C (55°F). Expect quite a bit of rainfall. Around 111 mm (4.4 in) is typical.

Rainfall in Merrillville in September

Rain is expected on roughly 9 days, totalling around 111 mm (4.4 in) for the month. The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.

Temperature in Merrillville in September

Temperatures in Merrillville in September top out at 25°C (77°F) and drop to 13°C (55°F) overnight. Overall, the month follows a fairly predictable daily temperature pattern. Nights cool down to 13°C (55°F), so a light jacket or extra layer is useful once the sun goes down. On the plus side, the cooler nights make for comfortable sleeping conditions.

Sunshine in Merrillville in September

The month enjoys around 226 hours of sunshine, creating mostly sunny days with good weather conditions.

If your ideal day consists of dry skies and pleasant temperatures, May, June, July, August and September typically offer the best circumstances for Merrillville.

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Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Merrillville's climate page.

Merrillville Temperature in September

Min Temperature 13°C (55°F)  

Max Temperature 25°C (77°F)  

Chance of Rain 30%  

Precipitation 111 mm (4.4 in)  

Rainy days 9 days  

Humidity 71% *  

Sunshine 226 hours *  

Percentage Sunshine 60% *  

* Data from: Chicago, the United States of America (72 KM, 45 Miles).

What to Wear in Merrillville in September

For Merrillville in September, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. High rain levels are expected, so pack waterproof gear and an umbrella or poncho. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.

What To Do in Merrillville in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

9/10

Cycling

9/10

Walking

9/10

Camping

6/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Merrillville's climate page.

More climate data for Merrillville

Temperature Rainfall Sunshine Humidity

See the full Merrillville climate overview or explore weather in the United States of America.