Climate and monthly weather forecastAltamont, IL
Climate and monthly weather forecast
Weather in January
January, like December, in Altamont, Illinois, is another cold winter month, with an average temperature fluctuating between 23.4°F (-4.8°C) and 35.6°F (2°C). The coldest time of the year is January, with temperatures averaging a high of 35.6°F (2°C) and a low of 23.4°F (-4.8°C). Weather in January »Weather in February
The last month of the winter, February, is another cold month in Altamont, Illinois, with an average temperature ranging between max 40.3°F (4.6°C) and min 26.6°F (-3°C). The transition into February shows a subtle variation to a still icy 40.3°F (4.6°C) from January's 35.6°F (2°C) in the average high-temperature. Weather in February »Weather in March
The first month of the spring, March, is a cool month in Altamont, Illinois, with temperature in the range of an average high of 52.2°F (11.2°C) and an average low of 36.9°F (2.7°C). In Altamont, the onset of March comes with an increased average high-temperature, moving from February's cold 40.3°F (4.6°C) to a fresh 52.2°F (11.2°C). Weather in March »Weather in April
April is a refreshing spring month in Altamont, Illinois, with temperature in the range of an average low of 46.6°F (8.1°C) and an average high of 63.5°F (17.5°C). Altamont in April sees a temperature change, with average high-temperatures moving from a cool 52.2°F (11.2°C) in March to a comfortable 63.5°F (17.5°C). Weather in April »Weather in May
The last month of the spring, May, is a warm month in Altamont, Illinois, with temperature in the range of an average high of 73.6°F (23.1°C) and an average low of 56.8°F (13.8°C). As April gives way to May, the average high-temperature displays an increase, moving from a refreshing 63.5°F (17.5°C) to a moderately hot 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 Altamont, Illinois, with temperature in the range of an average high of 81.7°F (27.6°C) and an average low of 65.5°F (18.6°C). As May transitions into June, a subtle temperature shift is observed, with average highs adjusting from 73.6°F (23.1°C) to a still moderately hot 81.7°F (27.6°C). Weather in June »Weather in July
July, the same as June, is another warm summer month in Altamont, Illinois, with an average temperature ranging between min 67.1°F (19.5°C) and max 83.7°F (28.7°C). In Altamont, July is the month with the highest recorded average temperatures, measuring a high of 83.7°F (28.7°C) and a low of 67.1°F (19.5°C). The heat index for July is computed to be a hot 93.2°F (34°C). Weather in July »Weather in August
The last month of the summer, August, is also a moderately hot month in Altamont, Illinois, with an average temperature fluctuating between 82.2°F (27.9°C) and 64.9°F (18.3°C). Altamont, Illinois, observes a minor difference in average high-temperatures between July's 83.7°F (28.7°C) and August's 82.2°F (27.9°C). Weather in August »Weather in September
The first month of the autumn, September, is still a warm month in Altamont, Illinois, with an average temperature fluctuating between 59.4°F (15.2°C) and 77.5°F (25.3°C). Altamont's shift into September is marked by a subtle change to a still moderately hot 77.5°F (25.3°C) from August's 82.2°F (27.9°C) in temperature. Weather in September »Weather in October
October, like September, in Altamont, Illinois, is another comfortable autumn month, with an average temperature ranging between min 48.6°F (9.2°C) and max 65.1°F (18.4°C). As October commences, the average high-temperature shows a reduction, transitioning from a moderately hot 77.5°F (25.3°C) in September to a refreshing 65.1°F (18.4°C). Weather in October »Weather in November
November, the last month of the autumn in Altamont, is also a fresh month, with an average temperature ranging between min 37°F (2.8°C) and max 51.4°F (10.8°C). As October transitions to November, the average high-temperature falls from an enjoyable 65.1°F (18.4°C) to a cool 51.4°F (10.8°C). Weather in November »Weather in December
The first month of the winter, December, is also a wintry month in Altamont, Illinois, with temperature in the range of an average high of 40.6°F (4.8°C) and an average low of 29.3°F (-1.5°C). Altamont, Illinois, experiences a temperature shift at the start of December, with average high-temperatures adjusting from a cool 51.4°F (10.8°C) in November to a wintry 40.6°F (4.8°C). Weather in December »Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Altamont, IL
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (35.6°F).
The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).
Average pressure
Altamont, 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:
29.95"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
Altamont, IL
- Average wind speed in January:
10.3mph - Average wind speed in February:
10.3mph - Average wind speed in March:
10mph - Average wind speed in April:
10mph - Average wind speed in May:
8.3mph - Average wind speed in June:
7.1mph
- Average wind speed in July:
6mph - Average wind speed in August:
6mph - Average wind speed in September:
6.7mph - Average wind speed in October:
8.7mph - Average wind speed in November:
9.4mph - Average wind speed in December:
9.4mph
The windiest months (with the highest average wind speed) are January and February (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity
Altamont, IL
The months with the highest relative humidity are July and August (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall
Altamont, IL
- Average rainfall in January:
1.77" - Average rainfall in February:
1.38" - Average rainfall in March:
2.32" - Average rainfall in April:
3.35" - Average rainfall in May:
2.91" - Average rainfall in June:
3.11"
- Average rainfall in July:
2.56" - Average rainfall in August:
2.32" - Average rainfall in September:
1.54" - Average rainfall in October:
2.05" - Average rainfall in November:
1.69" - Average rainfall in December:
1.77"
The wettest month (with the highest rainfall) is April (3.35").
The driest month (with the least rainfall) is February (1.38").
Average rainfall days
Altamont, IL
- Average rainfall days in January:
7.3 days - Average rainfall days in February:
7.6 days - Average rainfall days in March:
13.3 days - Average rainfall days in April:
14.3 days - Average rainfall days in May:
17.5 days - Average rainfall days in June:
14.5 days
- Average rainfall days in July:
15.8 days - Average rainfall days in August:
12.5 days - Average rainfall days in September:
10.8 days - Average rainfall days in October:
10.2 days - Average rainfall days in November:
8.9 days - Average rainfall days in December:
8.6 days
The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (7.3 days).
Average snowfall
Altamont, IL
The month with the highest snowfall is January (2.01").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days
Altamont, IL
- Average snowfall days in January:
5.3 days - Average snowfall days in February:
4.8 days - Average snowfall days in March:
2.3 days - Average snowfall days in April:
0.3 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 days - Average snowfall days in November:
1.3 days - Average snowfall days in December:
3.7 days
The month with the highest number of snowfall days is January (5.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight / Average sunshine
Altamont, 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 30min - Average sunshine in March:
6h and 18min - Average sunshine in April:
8h and 12min - Average sunshine in May:
9h and 6min - Average sunshine in June:
10h and 30min
- Average sunshine in July:
10h and 12min - Average sunshine in August:
10h and 0min - Average sunshine in September:
9h and 12min - 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 30min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days
Altamont, IL
- Average sunshine days in January:
18.9 days - Average sunshine days in February:
15.8 days - Average sunshine days in March:
15.7 days - Average sunshine days in April:
13.9 days - Average sunshine days in May:
10.8 days - Average sunshine days in June:
12.4 days
- Average sunshine days in July:
13.1 days - Average sunshine days in August:
15.3 days - Average sunshine days in September:
17.1 days - Average sunshine days in October:
19.3 days - Average sunshine days in November:
18.8 days - Average sunshine days in December:
19.5 days
The month with the most sunshine days is December (19.5 days).
The month with the least sunshine days is May (10.8 days).
Average UV index
Altamont, 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
Altamont, IL
The month with the most cloud cover is January (Cloud cover 53).
The months with the least cloud cover are June and September (Cloud cover 29).
Average visibility
Altamont, 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).





