Climate and monthly weather forecastDenison, IA
Climate and monthly weather forecast
Weather in January
January, like December, is a freezing cold winter month in Denison, Iowa, with an average temperature varying between 14°F (-10°C) and 27°F (-2.8°C). January, on average, is the coldest month, registering a high temperature of 27°F (-2.8°C) and a low of 14°F (-10°C). Weather in January »Weather in February
The last month of the winter, February, is also a subzero cold month in Denison, Iowa, with temperature in the range of an average high of 30.7°F (-0.7°C) and an average low of 17.6°F (-8°C). With the advent of February, Denison experiences an average high-temperature of a still freezing cold 30.7°F (-0.7°C), mirroring a close resemblance to the previous month. Weather in February »Weather in March
The first month of the spring, March, is a frosty month in Denison, Iowa, with temperature in the range of an average high of 46.4°F (8°C) and an average low of 31.1°F (-0.5°C). As March arrives, a noticeable rise in the average high-temperature is witnessed, moving from a subzero cold 30.7°F (-0.7°C) in February to a chilly 46.4°F (8°C). Weather in March »Weather in April
April in Denison, Iowa, is a refreshing spring month, with temperature in the range of an average low of 41.7°F (5.4°C) and an average high of 58.5°F (14.7°C). Noticing a change, the average high-temperature during April moves from March's chilly 46.4°F (8°C) to a mild 58.5°F (14.7°C). Weather in April »Weather in May
The last month of the spring, May, is a pleasant month in Denison, Iowa, with an average temperature ranging between min 52.7°F (11.5°C) and max 69.4°F (20.8°C). May's arrival sees a rise in the average high-temperature, jumping from April's refreshing 58.5°F (14.7°C) to a pleasant 69.4°F (20.8°C). Weather in May »Weather in June
June, the first month of the summer in Denison, is a moderately hot month, with an average temperature ranging between min 62.8°F (17.1°C) and max 79.3°F (26.3°C). The shift into June is marked by a rise in the average high-temperature, moving from May's agreeable 69.4°F (20.8°C) to a warm 79.3°F (26.3°C). Weather in June »Weather in July
July, the same as June, is another warm summer month in Denison, Iowa, with temperature in the range of an average high of 81.7°F (27.6°C) and an average low of 64.8°F (18.2°C). July is Denison's warmest month, registering average high temperatures of 81.7°F (27.6°C) and lows of 64.8°F (18.2°C). The heat index value during July is evaluated at a tropical 87.8°F (31°C). Weather in July »Weather in August
August, the last month of the summer in Denison, is another warm month, with an average temperature varying between 79.7°F (26.5°C) and 61.7°F (16.5°C). The transition into August marks the average high-temperature at a still warm 79.7°F (26.5°C), differing minimally from July's 81.7°F (27.6°C). Weather in August »Weather in September
September, the first month of the autumn in Denison, is still a warm month, with temperature in the range of an average high of 74.5°F (23.6°C) and an average low of 55.6°F (13.1°C). Denison registers an average high-temperature of a still warm 74.5°F (23.6°C) with the arrival of September, showing minor deviation from the preceding month. Weather in September »Weather in October
October, like September, is a moderate autumn month in Denison, Iowa, with an average temperature ranging between max 59.2°F (15.1°C) and min 43.7°F (6.5°C). Witnessing a clear downswing, the average high-temperature during October drops from September's warm 74.5°F (23.6°C) to a moderate 59.2°F (15.1°C). Weather in October »Weather in November
November, the last month of the autumn in Denison, is also a frosty month, with an average temperature varying between 32°F (0°C) and 45.9°F (7.7°C). The shift from October to November involves a decrease in the average high-temperature, dropping from a mild 59.2°F (15.1°C) to a chilly 45.9°F (7.7°C). Weather in November »Weather in December
December, the first month of the winter in Denison, is also a subzero cold month, with temperature in the range of an average high of 31.8°F (-0.1°C) and an average low of 20.3°F (-6.5°C). The arrival of December corresponds with a reduction in the average high-temperature, down from November's frosty 45.9°F (7.7°C) to a subzero cold 31.8°F (-0.1°C). Weather in December »Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Denison, IA
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (27°F).
The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (14°F).
Average pressure
Denison, IA
- Average pressure in January:
30.16"Hg - Average pressure in February:
30.15"Hg - Average pressure in March:
30.06"Hg - Average pressure in April:
29.92"Hg - Average pressure in May:
29.93"Hg - Average pressure in June:
29.87"Hg
- Average pressure in July:
29.95"Hg - Average pressure in August:
29.96"Hg - Average pressure in September:
30"Hg - Average pressure in October:
30"Hg - Average pressure in November:
30.08"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 (29.87"Hg).
Average wind speed
Denison, IA
- Average wind speed in January:
10.9mph - Average wind speed in February:
10.8mph - Average wind speed in March:
10.9mph - Average wind speed in April:
11.1mph - Average wind speed in May:
9.4mph - Average wind speed in June:
8.8mph
- Average wind speed in July:
7.4mph - Average wind speed in August:
7.6mph - Average wind speed in September:
8.7mph - Average wind speed in October:
9.9mph - Average wind speed in November:
10.6mph - Average wind speed in December:
10.4mph
The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest month (with the lowest average wind speed) is July (7.4mph).
Average humidity
Denison, IA
The month with the highest relative humidity is January (83%).
The months with the lowest relative humidity are April and October (68%).
Average rainfall
Denison, IA
- Average rainfall in January:
0.71" - Average rainfall in February:
0.91" - Average rainfall in March:
1.61" - Average rainfall in April:
2.36" - Average rainfall in May:
3.82" - Average rainfall in June:
3.5"
The wettest month (with the highest rainfall) is May (3.82").
The driest month (with the least rainfall) is January (0.71").
Average rainfall days
Denison, IA
- Average rainfall days in January:
3.6 days - Average rainfall days in February:
3 days - Average rainfall days in March:
9.4 days - Average rainfall days in April:
13.7 days - Average rainfall days in May:
16 days - Average rainfall days in June:
16.5 days
- Average rainfall days in July:
14 days - Average rainfall days in August:
13.7 days - Average rainfall days in September:
11.8 days - Average rainfall days in October:
10.4 days - Average rainfall days in November:
6.4 days - Average rainfall days in December:
4.5 days
The month with the highest number of rainy days is June (16.5 days).
The month with the least rainy days is February (3 days).
Average snowfall
Denison, IA
- Average snowfall in January:
3.35" - Average snowfall in February:
3.43" - Average snowfall in March:
2.68" - Average snowfall in April:
0.94" - Average snowfall in May:
0.12" - Average snowfall in June:
0"
The month with the highest snowfall is February (3.43").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Denison, IA
- Average snowfall days in January:
10.2 days - Average snowfall days in February:
8.3 days - Average snowfall days in March:
5.1 days - Average snowfall days in April:
1.4 days - Average snowfall days in May:
0.1 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:
0.8 days - Average snowfall days in November:
2.9 days - Average snowfall days in December:
8 days
The month with the highest number of snowfall days is January (10.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Denison, IA
- Average daylight in January:
9h and 30min - 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 36min - Average daylight in June:
15h and 12min
- Average daylight in July:
14h and 54min - 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 48min - Average daylight in December:
9h and 12min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in January:
4h and 12min - Average sunshine in February:
5h and 0min - Average sunshine in March:
6h and 0min - Average sunshine in April:
7h and 54min - Average sunshine in May:
8h and 36min - Average sunshine in June:
9h and 42min
- Average sunshine in July:
10h and 18min - Average sunshine in August:
9h and 30min - Average sunshine in September:
9h and 0min - Average sunshine in October:
5h and 48min - Average sunshine in November:
5h and 36min - Average sunshine in December:
4h and 42min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days
Denison, IA
- Average sunshine days in January:
18 days - Average sunshine days in February:
16.9 days - Average sunshine days in March:
16.4 days - Average sunshine days in April:
13.3 days - Average sunshine days in May:
13.2 days - Average sunshine days in June:
11.9 days
- Average sunshine days in July:
14.8 days - Average sunshine days in August:
15 days - Average sunshine days in September:
16.1 days - Average sunshine days in October:
18.8 days - Average sunshine days in November:
20.4 days - Average sunshine days in December:
19.7 days
The month with the most sunshine days is November (20.4 days).
The month with the least sunshine days is June (11.9 days).
Average UV index
Denison, IA
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is February (UV index 1).
Average cloud cover
Denison, IA
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility
Denison, IA
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).





