Climate and monthly weather forecastDuncan, IA
Climate and monthly weather forecast
Weather in January
January, the same as December, in Duncan, Iowa, is a freezing cold winter month, with temperature in the range of an average low of 10.4°F (-12°C) and an average high of 22.8°F (-5.1°C). Duncan's January weather, marked by an average high temperature of 22.8°F (-5.1°C) and an average low temperature of 10.4°F (-12°C), is the coldest in the year. Weather in January »Weather in February
The last month of the winter, February, is also a subzero cold month in Duncan, Iowa, with an average temperature varying between 26.4°F (-3.1°C) and 13.6°F (-10.2°C). As Duncan, Iowa, transitions from January to February, the average high-temperatures adjust to a still freezing cold 26.4°F (-3.1°C), nearly the same as the previous 22.8°F (-5.1°C). Weather in February »Weather in March
The first month of the spring, March, is a wintry month in Duncan, Iowa, with an average temperature fluctuating between 42.1°F (5.6°C) and 28.2°F (-2.1°C). March brings with it a considerable temperature increase, with average high-temperatures rising from February's freezing cold 26.4°F (-3.1°C) to a wintry 42.1°F (5.6°C). Weather in March »Weather in April
April in Duncan, Iowa, is a refreshing spring month, with an average temperature fluctuating between 55.8°F (13.2°C) and 39.9°F (4.4°C). A rise in the average high-temperature is observed during April, moving from a cold 42.1°F (5.6°C) in March to a mild 55.8°F (13.2°C). Weather in April »Weather in May
May, the last month of the spring in Duncan, is a pleasant month, with temperature in the range of an average low of 51.8°F (11°C) and an average high of 68°F (20°C). Duncan sees an increase in average high-temperatures during May, moving from a mild 55.8°F (13.2°C) in April to a pleasant 68°F (20°C). Weather in May »Weather in June
June, the first month of the summer in Duncan, is a moderately hot month, with an average temperature varying between 61.3°F (16.3°C) and 77.5°F (25.3°C). As June arrives, Duncan's weather shows an increase in high-temperatures, moving from May's pleasant 68°F (20°C) to a moderately hot 77.5°F (25.3°C). Weather in June »Weather in July
July, the same as June, is another warm summer month in Duncan, Iowa, with an average temperature fluctuating between 79.7°F (26.5°C) and 63°F (17.2°C). July, with an average high of 79.7°F (26.5°C) and a low of 63°F (17.2°C), signifies the warmest month of the year. Weather in July »Weather in August
August, the last month of the summer in Duncan, is another warm month, with an average temperature fluctuating between 60.3°F (15.7°C) and 77.9°F (25.5°C). With the arrival of August, Duncan's average high-temperature registers at a still moderately hot 77.9°F (25.5°C), indicating a subtle variation from the previous month. Weather in August »Weather in September
The first month of the autumn, September, is also an agreeable month in Duncan, Iowa, with an average temperature varying between 72.7°F (22.6°C) and 54°F (12.2°C). The average high-temperature during September registers at an agreeable 72.7°F (22.6°C), closely corresponding to the preceding month. Weather in September »Weather in October
October, the same as September, in Duncan, Iowa, is another refreshing autumn month, with an average temperature varying between 57.7°F (14.3°C) and 42.6°F (5.9°C). In Duncan, the average high-temperature in October significantly decreases from an agreeable 72.7°F (22.6°C) in September to a moderate 57.7°F (14.3°C). Weather in October »Weather in November
November, the last month of the autumn in Duncan, is another chilly month, with an average temperature fluctuating between 42.8°F (6°C) and 30.4°F (-0.9°C). A noticeable downshift in temperatures is seen as October gives way to November, with average highs moving from a moderate 57.7°F (14.3°C) to a chilly 42.8°F (6°C). Weather in November »Weather in December
December, the first month of the winter in Duncan, is also a subzero cold month, with an average temperature ranging between min 17.8°F (-7.9°C) and max 28.2°F (-2.1°C). The start of December brings a distinct shift in the average high-temperature, dropping from November's chilly 42.8°F (6°C) to a freezing cold 28.2°F (-2.1°C). Weather in December »Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Duncan, IA
The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (22.8°F).
The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (10.4°F).
Average pressure
Duncan, IA
- Average pressure in January:
30.15"Hg - Average pressure in February:
30.14"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.93"Hg - Average pressure in May:
29.93"Hg - Average pressure in June:
29.88"Hg
- Average pressure in July:
29.96"Hg - Average pressure in August:
29.96"Hg - Average pressure in September:
30.01"Hg - Average pressure in October:
29.99"Hg - Average pressure in November:
30.07"Hg - Average pressure in December:
30.11"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed
Duncan, IA
- Average wind speed in January:
10.9mph - Average wind speed in February:
10.8mph - Average wind speed in March:
10.7mph - Average wind speed in April:
11mph - Average wind speed in May:
9.6mph - Average wind speed in June:
8.5mph
- Average wind speed in July:
7.4mph - Average wind speed in August:
7.5mph - Average wind speed in September:
8.6mph - Average wind speed in October:
10.1mph - Average wind speed in November:
10.7mph - Average wind speed in December:
10.3mph
The windiest month (with the highest average wind speed) is April (11mph).
The calmest month (with the lowest average wind speed) is July (7.4mph).
Average humidity
Duncan, IA
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is October (69%).
Average rainfall
Duncan, IA
- Average rainfall in January:
0.94" - Average rainfall in February:
1.22" - Average rainfall in March:
1.54" - Average rainfall in April:
2.76" - Average rainfall in May:
3.15" - Average rainfall in June:
3.82"
The wettest month (with the highest rainfall) is June (3.82").
The driest month (with the least rainfall) is January (0.94").
Average rainfall days
Duncan, IA
- Average rainfall days in January:
4.3 days - Average rainfall days in February:
2.8 days - Average rainfall days in March:
9.6 days - Average rainfall days in April:
14.5 days - Average rainfall days in May:
16 days - Average rainfall days in June:
17.8 days
- Average rainfall days in July:
14.6 days - Average rainfall days in August:
12.4 days - Average rainfall days in September:
11.5 days - Average rainfall days in October:
10.7 days - Average rainfall days in November:
7.4 days - Average rainfall days in December:
5.5 days
The month with the highest number of rainy days is June (17.8 days).
The month with the least rainy days is February (2.8 days).
Average snowfall
Duncan, IA
- Average snowfall in January:
4.72" - Average snowfall in February:
5.71" - Average snowfall in March:
3.03" - Average snowfall in April:
1.77" - Average snowfall in May:
0.35" - Average snowfall in June:
0"
The month with the highest snowfall is February (5.71").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Duncan, IA
- Average snowfall days in January:
13.3 days - Average snowfall days in February:
10.4 days - Average snowfall days in March:
7.1 days - Average snowfall days in April:
2.6 days - Average snowfall days in May:
0.3 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:
1.5 days - Average snowfall days in November:
4.8 days - Average snowfall days in December:
11.2 days
The month with the highest number of snowfall days is January (13.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Duncan, IA
- Average daylight in January:
9h and 24min - 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 42min - Average daylight in June:
15h and 18min
- Average daylight in July:
15h and 0min - Average daylight in August:
13h and 54min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 42min - Average daylight in December:
9h and 6min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in January:
3h and 42min - Average sunshine in February:
4h and 12min - Average sunshine in March:
5h and 48min - Average sunshine in April:
7h and 42min - Average sunshine in May:
8h and 36min - Average sunshine in June:
9h and 24min
- Average sunshine in July:
9h and 48min - Average sunshine in August:
9h and 42min - Average sunshine in September:
9h and 0min - Average sunshine in October:
5h and 24min - Average sunshine in November:
5h and 18min - Average sunshine in December:
4h and 12min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days
Duncan, IA
- Average sunshine days in January:
16.4 days - Average sunshine days in February:
15.8 days - Average sunshine days in March:
15.8 days - Average sunshine days in April:
12.3 days - Average sunshine days in May:
13.5 days - Average sunshine days in June:
10.4 days
- Average sunshine days in July:
14.3 days - Average sunshine days in August:
16.8 days - Average sunshine days in September:
16.4 days - Average sunshine days in October:
17.5 days - Average sunshine days in November:
18.3 days - Average sunshine days in December:
16.6 days
The month with the most sunshine days is November (18.3 days).
The month with the least sunshine days is June (10.4 days).
Average UV index
Duncan, IA
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover
Duncan, IA
The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are August and September (Cloud cover 32).
Average visibility
Duncan, IA
The months with the highest visibility are February, March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January and July (5mi).





