Climate and monthly weather forecastMerrillville, IN
Climate and monthly weather forecast
The climate of Merrillville
Merrillville, Indiana, enjoys a humid continental climate, as per the Köppen climate classification and is quite harmonious with the state's Midwestern geographical position. The Dfa classification denotes that there is no dry season and the summers tend to be hot.Throughout the year, monthly temperatures range from 18.9°F (-7.3°C) to 81.5°F (27.5°C), indicating a variety in weather conditions across the seasons. Viewing summer months, June to August, reports a spike in temperatures - from the highs in the late 70s to low 80s°F and lows in the 60s°F. However, the winter months of December to February register temperatures between 18.9°F (-7.3°C) and a maximum of 33.4°F (0.8°C).
Humidity levels maintain the same pattern with margins between 73% to 83%, the dampness of the air gradually increasing during the peak months of summer and dropping towards the end of the year. Rainfall sees a consistent upward trend from January to June, before slightly backsliding. The most abundant rainfall months are May and June with 16.2 and 16.6 rainfall days respectively, while the driest months are February and December with around 5.3 and 5.6 rainfall days respectively.
The best time to visit Merrillville
Given the suitability of the climate for outdoor activities, the period from May to September is regarded as the ideal time to visit Merrillville. During these months, the high temperatures range from 69.3°F (20.7°C) to 81.5°F (27.5°C), offering comfortable warmth for sightseeing and other outdoor adventures. Visitors can enjoy around 14.5 daylight hours in May with even more extended daylight experience in June and July, both being 15.1 and 14.8 hours respectively.The worst time to visit Merrillville
Traveling to Merrillville during the winter months of December to February may not be ideal due to the low temperatures swinging between 18.9°F (-7.3°C) and 33.4°F (0.8°C), coupled with a considerable amount of snowfall. Snowfall reaches its peak during January, with 3.5" (89mm) of snow being registered on average, and as many as 11.3 snowfall days. Lower daylight hours, reaching a minimum of 9.2 in December, can also curb outdoor activities during these months.Spring weather in Merrillville
Spring in Merrillville, spanning the months of March, April, and May shows a steady transition from cooler to warmer temperatures. High temperatures in spring range from 45.9°F (7.7°C) in March to 69.3°F (20.7°C) in May, while low temperatures climb from 32.2°F (0.1°C) to 52.3°F (11.3°C). Despite the higher frequency of rainfall days, the recorded rainfall inches scale from 1.26" (32mm) in March to 3.03" (77mm) in May.Summer weather in Merrillville
During the summer months spanning from June to August, high temperatures rise from 78.4°F (25.8°C) to 81.5°F (27.5°C), cooling slightly to 79.5°F (26.4°C) in August. The period also experiences relatively higher rainfall days, albeit with a lesser amount of rain, the measurements sliding from 3.15" (80mm) in June to 2.48" (63mm) in August.Autumn weather in Merrillville
September ushers in Autumn, which continues through November. With a downward tilt in temperatures, high temperatures fall from 73.9°F (23.3°C) in September to 47.1°F (8.4°C) in November whereas low temperatures also slide from 57.7°F (14.3°C) to 35.2°F (1.8°C). There is a decreasing trend in rainfall days and amount from 2.48" (63mm) over 15.8 days in September to 1.06" (27mm) over 9.2 days in November.Winter weather in Merrillville
Winter characterizes the months starting December till February. These months face a consistent dip in temperature averages, with highs ranging from 36°F (2.2°C) in December to 33.4°F (0.8°C) in February and lows fluctuating between 26.6°F (-3°C) and 18.9°F (-7.3°C). Snowfall, almost nonexistent throughout the year, surfaces in these months with a maximum of 3.5" (89mm) in January alone. Days of snowfall also see a surge from 9.9 in December to a pinnacle of 12.4 in January.Weather in January
January is characterized by cold, cloudy days in Merrillville, Indiana, with a gradual transition from 9.6 hours to 10.6 hours of daylight. The month registers a substantial average snowfall of 3.23" (82mm), filling the landscape with a winter wonderland aesthetic. Weather in January »Weather in February
As the calendar turns to February, a gradual warming trend is observed in Merrillville. Unlike January, the snowfall quantity experiences a slight decrease. Individuals can still enjoy winter activities, but with frequent cloudy days, it's an opportune time to appreciate the beauty of indoors as well. Weather in February »Weather in March
The arrival of March marks the onset of spring climate in Merrillville. The snowfall is slim to none and the ground begins to thaw as the low temperature rises to 32.2°F (0.1°C). The duration of daylight expands to 12 hours and coupled with a UV index of 3, it signifies the resurgence of outdoor activities. Weather in March »Weather in April
April in Merrillville witnesses a significant transformation in weather conditions. Comparatively, rainfall increases from 1.26" (32mm) in March to 2.44" (62mm), making this the month with one of the highest rainfalls. The enhanced rainfall combined with the blossoming mid-spring flora paints a serene, green canvas across the city. Weather in April »Weather in May
May in Merrillville ushers in warmer temperatures and greater sunshine. Almost void of snowfall days, the city transitions fully into a lively late spring weather pattern. This month is also characterized by an extended daylight period which contributes to a vibrant outdoor life. Weather in May »Weather in June
June, often being the climatological peak of spring, expresses warm and comfortable weather in Merrillville. The average high temperature hits a mark of 78.4°F (25.8°C), leading to enjoyable summer activities. With an average of 15.1 hours of daylight, the days are long and sunny. Weather in June »Weather in July
July in Merrillville is characterized by the highest temperatures of the year, with an average high temperature peaking to 81.5°F (27.5°C). The hot weather combined with the most extended daylight hours of 14.8 hours catalyzes a full-on summer environment. Weather in July »Weather in August
Although August sees a slight dip in temperatures when compared to July, it is still a truly warm summer month in Merrillville. Very similar to July, the weather remains predominantly warm with ample sunny days. These conditions combined with the ongoing extended daylight hours, provide plenty of opportunities for outdoor activities. Weather in August »Weather in September
September marks the start of fall in Merrillville with a gradual decrease in daylight hours from 13.8 in August to 12.5. The transition from summer to fall is subtle with average high temperatures decreasing to 73.9°F (23.3°C), making it a pleasant time to visit the city. Weather in September »Weather in October
October embodies the essence of fall in Merrillville. The city witnesses a considerable drop in temperatures from September, signaling the approach of winter. With the charming fall scenery combined with cool temperatures, it's a perfect time for warm beverages and cozy sweaters. Weather in October »Weather in November
November in Merrillville tends to experience more cloudy days as the average cloud coverage rate goes up to 46% from October's 42%. Along with an increase in cloudiness, a decrease in temperatures is noted as winter approaches. Weather in November »Weather in December
December holds the onset of winter in Merrillville with temperatures dropping to an average low of 26.6°F (-3°C). Snowfall resumes after a break since April, covering everything in beautiful white. Although days are short, the bright winter sun combined with gleaming snow creates a stunning, festive vista. Weather in December »Updated: Jul 24, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Merrillville's coldest temperatures are experienced in January, with average high temperatures of 30°F (-1.1°C) and lows of 18.9°F (-7.3°C).
Throughout the year, there are 146.6 rainfall days, and 23.31" (592mm) of precipitation is accumulated.
January through April, October through December are months with snowfall.
Throughout the year, there are 45.5 snowfall days, and 12.64" (321mm) of snow is accumulated.
With an average of 3.5h of sunshine, January has the least sunshine of the year in Merrillville.
The months with the lowest UV index are January and December, with an average maximum UV index of 1.
With an average relative humidity of 83%, February is the most humid month.
February is the month with the most snowfall. Snow falls for 11.3 days and accumulates 3.5" (89mm) of snow.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from CST to CDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from CDT to CST.
May through September are months without snowfall.
The month with the most rainfall is June, when the rain falls for 16.6 days and typically aggregates up to 3.15" (80mm) of precipitation.
June has the longest days of the year, with an average of 15h and 6min of daylight.
June and July, with an average maximum UV index of 6, are months with the highest UV index.
July is the warmest month, with an average high-temperature of 81.5°F (27.5°C) and an average low-temperature of 65.5°F (18.6°C).
With an average of 9.8h of sunshine, August has the most sunshine of the year in Merrillville.
The least humid month is October, with an average relative humidity of 73%.
The month with the least rainfall is November, when the rain falls for 9.2 days and typically collects 1.06" (27mm) of precipitation.
With an average of 9h and 12min of daylight, December has the shortest days of the year.
Average temperature
Merrillville, IN
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (30°F).
The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure
Merrillville, IN
- Average pressure in January:
30.11"Hg - Average pressure in February:
30.09"Hg - Average pressure in March:
30.09"Hg - Average pressure in April:
29.95"Hg - Average pressure in May:
29.97"Hg - Average pressure in June:
29.93"Hg
- Average pressure in July:
29.97"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
30.03"Hg - Average pressure in October:
30.01"Hg - Average pressure in November:
30.1"Hg - Average pressure in December:
30.09"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed
Merrillville, IN
- Average wind speed in January:
10.3mph - Average wind speed in February:
9.9mph - Average wind speed in March:
9.5mph - Average wind speed in April:
9.8mph - Average wind speed in May:
8.3mph - Average wind speed in June:
7.4mph
- Average wind speed in July:
6.4mph - Average wind speed in August:
6.3mph - Average wind speed in September:
7.3mph - Average wind speed in October:
9.1mph - Average wind speed in November:
9.8mph - Average wind speed in December:
9.6mph
The windiest month (with the highest average wind speed) is January (10.3mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity
Merrillville, IN
The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is October (73%).
Average rainfall
Merrillville, IN
- Average rainfall in January:
1.1" - Average rainfall in February:
1.18" - Average rainfall in March:
1.26" - Average rainfall in April:
2.44" - Average rainfall in May:
3.03" - Average rainfall in June:
3.15"
- Average rainfall in July:
2.83" - Average rainfall in August:
2.48" - Average rainfall in September:
1.85" - Average rainfall in October:
1.81" - Average rainfall in November:
1.06" - Average rainfall in December:
1.1"
The wettest month (with the highest rainfall) is June (3.15").
The driest month (with the least rainfall) is November (1.06").
Average rainfall days
Merrillville, IN
- Average rainfall days in January:
5.6 days - Average rainfall days in February:
5.3 days - Average rainfall days in March:
11.7 days - Average rainfall days in April:
15.1 days - Average rainfall days in May:
16.2 days - Average rainfall days in June:
16.6 days
- Average rainfall days in July:
17.6 days - Average rainfall days in August:
15.8 days - Average rainfall days in September:
12.7 days - Average rainfall days in October:
13.1 days - Average rainfall days in November:
9.2 days - Average rainfall days in December:
7.7 days
The month with the highest number of rainy days is July (17.6 days).
The month with the least rainy days is February (5.3 days).
Average snowfall
Merrillville, IN
The month with the highest snowfall is February (3.5").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Merrillville, IN
- Average snowfall days in January:
12.4 days - Average snowfall days in February:
11.3 days - Average snowfall days in March:
5.8 days - Average snowfall days in April:
1.8 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.4 days - Average snowfall days in November:
3.9 days - Average snowfall days in December:
9.9 days
The month with the highest number of snowfall days is January (12.4 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Merrillville, IN
- Average daylight in January:
9h and 36min - Average daylight in February:
10h and 36min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 24min - Average daylight in May:
14h and 30min - Average daylight in June:
15h and 6min
- Average daylight in July:
14h and 48min - Average daylight in August:
13h and 48min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 6min - Average daylight in November:
9h and 54min - Average daylight in December:
9h and 12min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in January:
3h and 30min - Average sunshine in February:
3h and 42min - Average sunshine in March:
5h and 48min - Average sunshine in April:
7h and 24min - Average sunshine in May:
8h and 30min - Average sunshine in June:
9h and 36min
- Average sunshine in July:
9h and 42min - Average sunshine in August:
9h and 48min - Average sunshine in September:
8h and 18min - Average sunshine in October:
5h and 48min - Average sunshine in November:
5h and 0min - Average sunshine in December:
3h and 54min
The month with the most sunshine is August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days
Merrillville, IN
- Average sunshine days in January:
14.3 days - Average sunshine days in February:
12.7 days - Average sunshine days in March:
14.8 days - Average sunshine days in April:
12 days - Average sunshine days in May:
12 days - Average sunshine days in June:
11.5 days
- Average sunshine days in July:
10.2 days - Average sunshine days in August:
11.8 days - Average sunshine days in September:
14.5 days - Average sunshine days in October:
15.5 days - Average sunshine days in November:
17.4 days - Average sunshine days in December:
15.7 days
The month with the most sunshine days is November (17.4 days).
The month with the least sunshine days is July (10.2 days).
Average UV index
Merrillville, IN
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover
Merrillville, IN
The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility
Merrillville, IN
The months with the highest visibility are March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February and July (5mi).
