Climate and monthly weather forecastIllmo, MO
Climate and monthly weather forecast
Weather in January
January, like December, in Illmo, Missouri, is a wintry winter month, with temperature in the range of an average high of 41°F (5°C) and an average low of 27.9°F (-2.3°C). Illmo's January weather, marked by an average high temperature of 41°F (5°C) and an average low temperature of 27.9°F (-2.3°C), is the coldest in the year. Weather in January »Weather in February
February, the last month of the winter in Illmo, is a frosty month, with an average temperature ranging between min 31.5°F (-0.3°C) and max 45.5°F (7.5°C). February brings an average high-temperature of a chilly 45.5°F (7.5°C), nearly identical to the preceding month. Weather in February »Weather in March
The first month of the spring, March, is a moderate month in Illmo, Missouri, with an average temperature fluctuating between 56.3°F (13.5°C) and 40.5°F (4.7°C). In Illmo, the average high-temperature in March rises, from a chilly 45.5°F (7.5°C) in February, to a moderate 56.3°F (13.5°C). Weather in March »Weather in April
April is a refreshing spring month in Illmo, Missouri, with an average temperature ranging between min 49.8°F (9.9°C) and max 67.1°F (19.5°C). April's arrival is marked by an increase in the average high-temperature, moving from a moderate 56.3°F (13.5°C) in March to a comfortable 67.1°F (19.5°C). Weather in April »Weather in May
The last month of the spring, May, is a moderately hot month in Illmo, Missouri, with an average temperature ranging between min 59°F (15°C) and max 76.3°F (24.6°C). Illmo's May weather brings a rise in high-temperatures, moving from a refreshing 67.1°F (19.5°C) in April to a moderately hot 76.3°F (24.6°C). Weather in May »Weather in June
The first month of the summer, June, is a tropical month in Illmo, Missouri, with an average temperature ranging between max 86°F (30°C) and min 67.5°F (19.7°C). Illmo's June weather shows an increase in high-temperatures, moving from May's moderately hot 76.3°F (24.6°C) to a tropical 86°F (30°C). Weather in June »Weather in July
July, like June, is a hot summer month in Illmo, Missouri, with an average temperature ranging between min 69.4°F (20.8°C) and max 88.3°F (31.3°C). Illmo's July weather, with an average high temperature of 88.3°F (31.3°C) and an average low temperature of 69.4°F (20.8°C), tends to be the warmest of the year. The heat index value for July is computed to be an extremely hot 104°F (40°C). Weather in July »Weather in August
The last month of the summer, August, is another hot month in Illmo, Missouri, with an average temperature fluctuating between 67.1°F (19.5°C) and 86.2°F (30.1°C). The transition into August notes an average high-temperature of a still tropical 86.2°F (30.1°C), revealing a mild distinction from the 88.3°F (31.3°C) in July. Weather in August »Weather in September
The first month of the autumn, September, is also a moderately hot month in Illmo, Missouri, with an average temperature fluctuating between 61.3°F (16.3°C) and 81.1°F (27.3°C). As Illmo, Missouri, welcomes September, the average high-temperature is noted at a moderately hot 81.1°F (27.3°C), closely aligning with the preceding month. Weather in September »Weather in October
October, the same as September, in Illmo, Missouri, is an agreeable autumn month, with temperature in the range of an average high of 68.9°F (20.5°C) and an average low of 50.7°F (10.4°C). October involves a decrease in temperature, down from a moderately hot 81.1°F (27.3°C) in September to a pleasant 68.9°F (20.5°C). Weather in October »Weather in November
The last month of the autumn, November, is also a fresh month in Illmo, Missouri, with an average temperature fluctuating between 54.7°F (12.6°C) and 39.7°F (4.3°C). As November commences, the average high-temperature shows a reduction, transitioning from a pleasant 68.9°F (20.5°C) in October to a fresh 54.7°F (12.6°C). Weather in November »Weather in December
The first month of the winter, December, is also a frosty month in Illmo, Missouri, with an average temperature ranging between min 33.1°F (0.6°C) and max 45.5°F (7.5°C). December shows a mild decline in the average high-temperature, falling from November's cool 54.7°F (12.6°C) to a frosty 45.5°F (7.5°C). Weather in December »Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Illmo, MO
The warmest month (with the highest average high temperature) is July (88.3°F).
The month with the lowest average high temperature is January (41°F).
The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (27.9°F).
Average pressure
Illmo, MO
- 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:
29.96"Hg - Average pressure in May:
29.97"Hg - Average pressure in June:
29.94"Hg
- Average pressure in July:
29.97"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
30.04"Hg - Average pressure in November:
30.14"Hg - Average pressure in December:
30.14"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed
Illmo, MO
- Average wind speed in January:
9.1mph - Average wind speed in February:
9.1mph - Average wind speed in March:
9mph - Average wind speed in April:
8.9mph - Average wind speed in May:
7.5mph - Average wind speed in June:
6.4mph
- Average wind speed in July:
5.7mph - Average wind speed in August:
5.7mph - Average wind speed in September:
6.2mph - Average wind speed in October:
7.7mph - Average wind speed in November:
8.4mph - Average wind speed in December:
8.6mph
The windiest months (with the highest average wind speed) are January and February (9.1mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).
Average humidity
Illmo, MO
The months with the highest relative humidity are March and May (78%).
The month with the lowest relative humidity is October (69%).
Average rainfall
Illmo, MO
- Average rainfall in January:
2.32" - Average rainfall in February:
3.07" - Average rainfall in March:
3.54" - Average rainfall in April:
4.33" - Average rainfall in May:
3.98" - Average rainfall in June:
2.99"
- Average rainfall in July:
2.91" - Average rainfall in August:
2.72" - Average rainfall in September:
1.5" - Average rainfall in October:
2.83" - Average rainfall in November:
2.95" - Average rainfall in December:
2.44"
The wettest month (with the highest rainfall) is April (4.33").
The driest month (with the least rainfall) is September (1.5").
Average rainfall days
Illmo, MO
- Average rainfall days in January:
9.8 days - Average rainfall days in February:
11.6 days - Average rainfall days in March:
15.3 days - Average rainfall days in April:
15.3 days - Average rainfall days in May:
16.8 days - Average rainfall days in June:
15.6 days
- Average rainfall days in July:
17 days - Average rainfall days in August:
14.4 days - Average rainfall days in September:
11.4 days - Average rainfall days in October:
10.5 days - Average rainfall days in November:
10.1 days - Average rainfall days in December:
10.8 days
The month with the highest number of rainy days is July (17 days).
The month with the least rainy days is January (9.8 days).
Average snowfall
Illmo, MO
The month with the highest snowfall is February (2.17").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Illmo, MO
- Average snowfall days in January:
3.7 days - Average snowfall days in February:
3.6 days - Average snowfall days in March:
1.3 days - Average snowfall days in April:
0.1 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:
0.1 days - Average snowfall days in November:
0.8 days - Average snowfall days in December:
1.6 days
The month with the highest number of snowfall days is January (3.7 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Illmo, MO
- Average daylight in January:
9h and 54min - Average daylight in February:
10h and 48min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 12min - Average daylight in May:
14h and 12min - Average daylight in June:
14h and 42min
- Average daylight in July:
14h and 24min - Average daylight in August:
13h and 30min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 12min - Average daylight in November:
10h and 12min - Average daylight in December:
9h and 42min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 42min).
- Average sunshine in January:
4h and 54min - Average sunshine in February:
4h and 48min - Average sunshine in March:
6h and 24min - Average sunshine in April:
8h and 42min - Average sunshine in May:
9h and 18min - Average sunshine in June:
10h and 42min
- Average sunshine in July:
10h and 36min - Average sunshine in August:
10h and 24min - Average sunshine in September:
9h and 42min - Average sunshine in October:
6h and 30min - Average sunshine in November:
5h and 36min - Average sunshine in December:
5h and 0min
The month with the most sunshine is June (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).
Average sunshine days
Illmo, MO
- Average sunshine days in January:
17.8 days - Average sunshine days in February:
13.8 days - Average sunshine days in March:
13.5 days - Average sunshine days in April:
13.1 days - Average sunshine days in May:
12.3 days - Average sunshine days in June:
12.4 days
- Average sunshine days in July:
11.9 days - Average sunshine days in August:
14.3 days - Average sunshine days in September:
16.9 days - Average sunshine days in October:
18.6 days - Average sunshine days in November:
18.5 days - Average sunshine days in December:
18.1 days
The month with the most sunshine days is October (18.6 days).
The month with the least sunshine days is July (11.9 days).
Average UV index
Illmo, MO
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover
Illmo, MO
The month with the most cloud cover is February (Cloud cover 48).
The months with the least cloud cover are June, August and September (Cloud cover 27).
Average visibility
Illmo, MO
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).





