Climate and monthly weather forecast
Old Saint Louis, IN

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Weather in January

January, like December, in Old Saint Louis, Indiana, is another cold winter month, with an average temperature varying between 35.2°F (1.8°C) and 22.5°F (-5.3°C). The month of January, characterized by an average high of 35.2°F (1.8°C) and a low of 22.5°F (-5.3°C), is recognized as the coldest. Weather in January »

Weather in February

The last month of the winter, February, is another cold month in Old Saint Louis, Indiana, with an average temperature ranging between min 26.1°F (-3.3°C) and max 39.9°F (4.4°C). February brings an average high-temperature of a still cold 39.9°F (4.4°C), nearly identical to the preceding month. Weather in February »

Weather in March

The first month of the spring, March, is a fresh month in Old Saint Louis, Indiana, with an average temperature varying between 35.6°F (2°C) and 51.1°F (10.6°C). March's arrival sees a rise in the average high-temperature, jumping from February's cold 39.9°F (4.4°C) to a fresh 51.1°F (10.6°C). Weather in March »

Weather in April

April is a refreshing spring month in Old Saint Louis, Indiana, with temperature in the range of an average low of 45.9°F (7.7°C) and an average high of 63.1°F (17.3°C). The shift from March to April brings an increase in the average high-temperature, moving from a fresh 51.1°F (10.6°C) to an enjoyable 63.1°F (17.3°C). Weather in April »

Weather in May

May, the last month of the spring in Old Saint Louis, is a pleasant month, with an average temperature fluctuating between 55.9°F (13.3°C) and 73°F (22.8°C). In May, the average high-temperature increases from an enjoyable 63.1°F (17.3°C) in April to an agreeable 73°F (22.8°C). Weather in May »

Weather in June

June, the first month of the summer in Old Saint Louis, is a moderately hot month, with temperature in the range of an average low of 63.3°F (17.4°C) and an average high of 81.1°F (27.3°C). The coming of June brings a minor shift in Old Saint Louis's weather, with average high-temperatures adjusting from May's pleasant 73°F (22.8°C) to a moderately hot 81.1°F (27.3°C). Weather in June »

Weather in July

July, the same as June, is another warm summer month in Old Saint Louis, Indiana, with temperature in the range of an average high of 83.3°F (28.5°C) and an average low of 65.5°F (18.6°C). July registers as the month with the highest average temperatures, reaching 83.3°F (28.5°C) at its peak and 65.5°F (18.6°C) at the lowest. In July, the heat index is calculated to be a hot 93.2°F (34°C). Weather in July »

Weather in August

The last month of the summer, August, is another warm month in Old Saint Louis, Indiana, with an average temperature fluctuating between 63.3°F (17.4°C) and 82.8°F (28.2°C). Old Saint Louis commences August with an average high-temperature of a still moderately hot 82.8°F (28.2°C), maintaining a close resemblance to the previous month. Weather in August »

Weather in September

The first month of the autumn, September, is also a moderately hot month in Old Saint Louis, Indiana, with an average temperature fluctuating between 58.3°F (14.6°C) and 77°F (25°C). September sees a slight reduction in average high-temperature, with a shift from 82.8°F (28.2°C) in August to a still warm 77°F (25°C). Weather in September »

Weather in October

October, the same as September, is another refreshing autumn month in Old Saint Louis, Indiana, with an average temperature ranging between min 47.3°F (8.5°C) and max 64.6°F (18.1°C). October indicates a shift in the average high-temperature, from September's moderately hot 77°F (25°C) to a comfortable 64.6°F (18.1°C). Weather in October »

Weather in November

November, the last month of the autumn in Old Saint Louis, is also a fresh month, with an average temperature varying between 36.5°F (2.5°C) and 51.1°F (10.6°C). November indicates a shift in the average high-temperature, from October's refreshing 64.6°F (18.1°C) to a fresh 51.1°F (10.6°C). Weather in November »

Weather in December

The first month of the winter, December, is also an icy month in Old Saint Louis, Indiana, with temperature in the range of an average low of 29.7°F (-1.3°C) and an average high of 40.6°F (4.8°C). December's arrival correlates with a reduction in the average high-temperature, down from a fresh 51.1°F (10.6°C) in November to a wintry 40.6°F (4.8°C). Weather in December »
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What month is the coldest in Old Saint Louis?

Old Saint Louis notes the coldest temperatures in January, with a average high of 35.2°F (1.8°C) and a low of 22.5°F (-5.3°C).

What are the most humid months in Old Saint Louis?

January, February, July and December, with an average relative humidity of 81%, are most humid months in Old Saint Louis, Indiana.

How many days does it rain in Old Saint Louis?

Throughout the year, there are 163.5 rainfall days, and 29.29" (744mm) of precipitation is accumulated.

When does it snow in Old Saint Louis?

January through April, November and December are months with snowfall in Old Saint Louis, Indiana.

How much does it snow in Old Saint Louis?

In Old Saint Louis, during the entire year, snow falls for 34.1 days and aggregates up to 8.54" (217mm) of snow.

What is the month with the least sunshine in Old Saint Louis?

With an average of 4.1h of sunshine, January has the least sunshine of the year in Old Saint Louis.

What is the month with the lowest UV index in Old Saint Louis?

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.

When does it snow the most in Old Saint Louis?

February is the month with the most snowfall. Snow falls for 7.8 days and accumulates 2.17" (55mm) of snow.

When is Daylight Saving Time (DST) in Old Saint Louis?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Old Saint Louis, and the time zone changes from EST to EDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from EDT to EST.

What is the rainiest month in Old Saint Louis?

May is the month with the most rainfall. Rain falls for 18.3 days and accumulates 3.5" (89mm) of precipitation.

When it does not snow in Old Saint Louis?

May through October are months without snowfall in Old Saint Louis, Indiana.

When are the longest days in Old Saint Louis?

The month with the longest days in Old Saint Louis is June, with an average of 14h and 54min of daylight.

What are the months with the highest UV index in Old Saint Louis?

The months with the highest UV index are June through August, with an average maximum UV index of 6.

What is the warmest month in Old Saint Louis?

With average high and low temperatures of 83.3°F (28.5°C) and 65.5°F (18.6°C) respectively, July is Old Saint Louis's warmest month.

What month has the most sunshine in Old Saint Louis?

The month with the most sunshine is July, with an average of 10.4h of sunshine.

What is the driest month in Old Saint Louis?

The month with the least rainfall in Old Saint Louis, Indiana, is September, when the rain falls for 14.1 days and typically collects 1.73" (44mm) of precipitation.

What is the least humid month in Old Saint Louis?

October is the least humid month in Old Saint Louis, Indiana, with an average relative humidity of 74%.

What is the month with the shortest days in Old Saint Louis?

The month with the shortest days is December, with an average of 9h and 30min of daylight.

Average temperature
Old Saint Louis, IN

Average temperature - Old Saint Louis, IN

The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (35.2°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 (22.5°F).

Average pressure
Old Saint Louis, IN

Average pressure - Old Saint Louis, IN

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed
Old Saint Louis, IN

Average wind speed - Old Saint Louis, IN

The windiest months (with the highest average wind speed) are January and February (8.9mph).
The calmest months (with the lowest average wind speed) are July and August (5.3mph).

Average humidity
Old Saint Louis, IN

Average humidity - Old Saint Louis, IN

The months with the highest relative humidity are January, February, July and December (81%).
The month with the lowest relative humidity is October (74%).

Average rainfall
Old Saint Louis, IN

Average rainfall - Old Saint Louis, IN

The wettest month (with the highest rainfall) is May (3.5").
The driest month (with the least rainfall) is September (1.73").

Average rainfall days
Old Saint Louis, IN

Average rainfall days - Old Saint Louis, IN

The month with the highest number of rainy days is May (18.3 days).
The months with the least rainy days are January and February (9.4 days).

Average snowfall
Old Saint Louis, IN

Average snowfall - Old Saint Louis, IN

The month with the highest snowfall is February (2.17").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days
Old Saint Louis, IN

Average snowfall days - Old Saint Louis, IN

The month with the highest number of snowfall days is January (9.6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight / Average sunshine
Old Saint Louis, IN

Average daylight / Average sunshine - Old Saint Louis, IN

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days
Old Saint Louis, IN

Average sunshine days - Old Saint Louis, IN

The month with the most sunshine days is October (17.7 days).
The month with the least sunshine days is May (10.3 days).

Average UV index
Old Saint Louis, IN

Average UV index - Old Saint Louis, IN

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average visibility
Old Saint Louis, IN

Average visibility - Old Saint Louis, IN

The months with the highest visibility are January, February, March, April, May, June, August, September, October and November (6mi).
The months with the lowest visibility are July and December (5mi).

Old Saint Louis, Indiana, USA

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