Climate and monthly weather forecastVandalia, IL
Climate and monthly weather forecast
Weather in January
January, like December, in Vandalia, Illinois, is an icy winter month, with an average temperature ranging between max 36°F (2.2°C) and min 23.4°F (-4.8°C). January, with average temperatures reaching a high of 36°F (2.2°C) and a low of 23.4°F (-4.8°C), is the coldest month. Weather in January »Weather in February
February, the last month of the winter in Vandalia, is also a wintry month, with an average temperature fluctuating between 40.6°F (4.8°C) and 27°F (-2.8°C). February brings an average high-temperature of a still wintry 40.6°F (4.8°C), showing a slight difference from January's 36°F (2.2°C). Weather in February »Weather in March
The first month of the spring, March, is a cool month in Vandalia, Illinois, with an average temperature ranging between max 53.1°F (11.7°C) and min 36.9°F (2.7°C). March's arrival brings a temperature shift, moving from an icy 40.6°F (4.8°C) in February to a fresh 53.1°F (11.7°C). Weather in March »Weather in April
April in Vandalia, Illinois, is a comfortable spring month, with temperature in the range of an average high of 63.7°F (17.6°C) and an average low of 46.6°F (8.1°C). April sees a rise in the average high-temperature, climbing from a cool 53.1°F (11.7°C) in March to a comfortable 63.7°F (17.6°C). Weather in April »Weather in May
The last month of the spring, May, is a warm month in Vandalia, Illinois, with an average temperature ranging between max 73.6°F (23.1°C) and min 56.8°F (13.8°C). The shift into May is characterized by a rise in the average high-temperature, transitioning from April's comfortable 63.7°F (17.6°C) to a warm 73.6°F (23.1°C). Weather in May »Weather in June
The first month of the summer, June, is still a warm month in Vandalia, Illinois, with an average temperature fluctuating between 82.4°F (28°C) and 65.7°F (18.7°C). As Vandalia welcomes June, the average high-temperature sees a modest rise, transitioning from 73.6°F (23.1°C) in May to a still warm 82.4°F (28°C). Weather in June »Weather in July
July, the same as June, is a moderately hot summer month in Vandalia, Illinois, with temperature in the range of an average low of 67.3°F (19.6°C) and an average high of 84°F (28.9°C). July temperatures tend to peak at an average high of 84°F (28.9°C) and dip to a low of 67.3°F (19.6°C). July's average heat index is appraised at a very hot 95°F (35°C). Weather in July »Weather in August
August, the last month of the summer in Vandalia, is another warm month, with an average temperature fluctuating between 82.6°F (28.1°C) and 65.1°F (18.4°C). The arrival of August is marked by an average high-temperature of a still moderately hot 82.6°F (28.1°C), bearing a close resemblance to July. Weather in August »Weather in September
The first month of the autumn, September, is still a warm month in Vandalia, Illinois, with an average temperature ranging between min 59.4°F (15.2°C) and max 77.9°F (25.5°C). September's onset brings an average high-temperature of a still moderately hot 77.9°F (25.5°C), showing a minute difference from August's 82.6°F (28.1°C). Weather in September »Weather in October
October, like September, in Vandalia, Illinois, is another refreshing autumn month, with an average temperature varying between 48.6°F (9.2°C) and 65.1°F (18.4°C). The onset of October comes with a shift in the average high-temperature, falling from a moderately hot 77.9°F (25.5°C) in September to a refreshing 65.1°F (18.4°C). Weather in October »Weather in November
The last month of the autumn, November, is also a fresh month in Vandalia, Illinois, with an average temperature varying between 51.8°F (11°C) and 37.2°F (2.9°C). The transition into November indicates a reduction in the average high-temperature, down to a fresh 51.8°F (11°C) from October's enjoyable 65.1°F (18.4°C). Weather in November »Weather in December
December, the first month of the winter in Vandalia, is also a wintry month, with temperature in the range of an average high of 41°F (5°C) and an average low of 29.5°F (-1.4°C). Stepping into December, Vandalia observes a temperature decline, with the average high falling from November's cool 51.8°F (11°C) to a cold 41°F (5°C). Weather in December »Updated: Aug 1, 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
January is the month when Vandalia experiences its coldest temperatures, averaging a high of 36°F (2.2°C) and a low of 23.4°F (-4.8°C).
In Vandalia, Illinois, during the entire year, the rain falls for 164.1 days and collects up to 36.73" (933mm) of precipitation.
Months with snowfall are January through April, November and December.
In Vandalia, Illinois, during the entire year, snow falls for 25.1 days and aggregates up to 8.19" (208mm) of snow.
With an average of 4.3h of sunshine, January has the least sunshine of the year.
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.
February is the month with the least rainfall. Rain falls for 9.6 days and accumulates 2.01" (51mm) of precipitation.
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 October are months without snowfall.
The month with the most rainfall in Vandalia is June, when the rain falls for 17.2 days and typically aggregates up to 4.57" (116mm) of precipitation.
June has the longest days of the year, with an average of 14h and 54min of daylight.
The month with the most sunshine is June, with an average of 10.3h of sunshine.
The months with the highest UV index are June through August, with an average maximum UV index of 6.
July is the month when Vandalia sees the average highest temperatures, with a high of 84°F (28.9°C) and a low of 67.3°F (19.6°C).
The most humid month is July, with an average relative humidity of 81%.
With an average relative humidity of 71%, October is the least humid month.
The month with the most snowfall is December, when snow falls for 5.1 days and typically aggregates up to 2.4" (61mm) of snow.
With an average of 9h and 30min of daylight, December has the shortest days of the year.
Average temperature
Vandalia, IL
The warmest month (with the highest average high temperature) is July (84°F).
The month with the lowest average high temperature is January (36°F).
The month with the highest average low temperature is July (67.3°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure
Vandalia, IL
- Average pressure in January:
30.16"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.94"Hg - Average pressure in May:
29.96"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:
30.03"Hg - Average pressure in November:
30.13"Hg - Average pressure in December:
30.13"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed
Vandalia, IL
- Average wind speed in January:
10.3mph - Average wind speed in February:
10.1mph - Average wind speed in March:
9.9mph - Average wind speed in April:
9.8mph - Average wind speed in May:
8.1mph - Average wind speed in June:
7mph
- Average wind speed in July:
6mph - Average wind speed in August:
6mph - Average wind speed in September:
6.6mph - Average wind speed in October:
8.6mph - Average wind speed in November:
9.3mph - Average wind speed in December:
9.3mph
The windiest month (with the highest average wind speed) is January (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity
Vandalia, IL
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall
Vandalia, IL
- Average rainfall in January:
2.36" - Average rainfall in February:
2.01" - Average rainfall in March:
2.99" - Average rainfall in April:
4.21" - Average rainfall in May:
4.09" - Average rainfall in June:
4.57"
- Average rainfall in July:
3.39" - Average rainfall in August:
3.07" - Average rainfall in September:
2.17" - Average rainfall in October:
3.11" - Average rainfall in November:
2.32" - Average rainfall in December:
2.44"
The wettest month (with the highest rainfall) is June (4.57").
The driest month (with the least rainfall) is February (2.01").
Average rainfall days
Vandalia, IL
- Average rainfall days in January:
9.2 days - Average rainfall days in February:
9.6 days - Average rainfall days in March:
15.1 days - Average rainfall days in April:
15.9 days - Average rainfall days in May:
18.3 days - Average rainfall days in June:
17.2 days
- Average rainfall days in July:
18 days - Average rainfall days in August:
15.6 days - Average rainfall days in September:
13.3 days - Average rainfall days in October:
11.6 days - Average rainfall days in November:
10.6 days - Average rainfall days in December:
9.7 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is January (9.2 days).
Average snowfall
Vandalia, IL
The month with the highest snowfall is December (2.4").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
Vandalia, IL
- Average snowfall days in January:
8.3 days - Average snowfall days in February:
7 days - Average snowfall days in March:
2.7 days - Average snowfall days in April:
0.5 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:
0.2 days - Average snowfall days in November:
1.3 days - Average snowfall days in December:
5.1 days
The month with the highest number of snowfall days is January (8.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Vandalia, IL
- Average daylight in January:
9h and 48min - Average daylight in February:
10h and 48min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 18min - Average daylight in May:
14h and 18min - Average daylight in June:
14h and 54min
- Average daylight in July:
14h and 36min - Average daylight in August:
13h and 36min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 12min - Average daylight in November:
10h and 6min - Average daylight in December:
9h and 30min
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).
- Average sunshine in January:
4h and 18min - Average sunshine in February:
4h and 24min - Average sunshine in March:
6h and 12min - Average sunshine in April:
8h and 6min - Average sunshine in May:
9h and 0min - Average sunshine in June:
10h and 18min
- Average sunshine in July:
10h and 12min - Average sunshine in August:
9h and 42min - Average sunshine in September:
9h and 6min - Average sunshine in October:
6h and 18min - Average sunshine in November:
5h and 24min - Average sunshine in December:
4h and 36min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days
Vandalia, IL
- Average sunshine days in January:
15.5 days - Average sunshine days in February:
13.3 days - Average sunshine days in March:
13.9 days - Average sunshine days in April:
11.9 days - Average sunshine days in May:
9.8 days - Average sunshine days in June:
9.3 days
- Average sunshine days in July:
8.6 days - Average sunshine days in August:
12 days - Average sunshine days in September:
14.7 days - Average sunshine days in October:
17.2 days - Average sunshine days in November:
17 days - Average sunshine days in December:
16.6 days
The month with the most sunshine days is October (17.2 days).
The month with the least sunshine days is July (8.6 days).
Average UV index
Vandalia, IL
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 cloud cover
Vandalia, IL
The month with the most cloud cover is January (Cloud cover 53).
The months with the least cloud cover are June, July and September (Cloud cover 30).
Average visibility
Vandalia, IL
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
