Climate and monthly weather forecastIona, SD
Climate and monthly weather forecast
Weather in January
January, the same as December, in Iona, South Dakota, is another subzero cold winter month, with an average temperature varying between 12.6°F (-10.8°C) and 26.1°F (-3.3°C). January brings the lowest temperatures, with an average high of 26.1°F (-3.3°C) and an average low of 12.6°F (-10.8°C). Weather in January »Weather in February
February, the last month of the winter in Iona, is another freezing cold month, with an average temperature varying between 29.8°F (-1.2°C) and 15.3°F (-9.3°C). Iona's weather, upon February's arrival, documents an average high-temperature of a still subzero cold 29.8°F (-1.2°C), nearly identical to the prior month. Weather in February »Weather in March
March, the first month of the spring in Iona, is a chilly month, with an average temperature ranging between min 29.1°F (-1.6°C) and max 45°F (7.2°C). The beginning of March marks a clear shift in the average high-temperature, advancing from February's freezing cold 29.8°F (-1.2°C) to a frosty 45°F (7.2°C). Weather in March »Weather in April
April in Iona, South Dakota, is a moderate spring month, with an average temperature ranging between max 56.3°F (13.5°C) and min 38.3°F (3.5°C). The beginning of April marks a shift in the average high-temperature, moving from March's frosty 45°F (7.2°C) to a mild 56.3°F (13.5°C). Weather in April »Weather in May
May, the last month of the spring in Iona, is a comfortable month, with an average temperature varying between 67.8°F (19.9°C) and 49.3°F (9.6°C). May brings a temperature change, with average high-temperatures moving from April's refreshing 56.3°F (13.5°C) to an enjoyable 67.8°F (19.9°C). Weather in May »Weather in June
June, the first month of the summer in Iona, is a moderately hot month, with an average temperature fluctuating between 60.4°F (15.8°C) and 79.7°F (26.5°C). The shift into June is accompanied by a temperature increase, with the average high-temperature rising from a refreshing 67.8°F (19.9°C) in May to a moderately hot 79.7°F (26.5°C). Weather in June »Weather in July
July in Iona, South Dakota, is a hot summer month, with an average temperature ranging between min 66.2°F (19°C) and max 88°F (31.1°C). July, with its average high-temperature of 88°F (31.1°C) and an average low-temperature of 66.2°F (19°C), holds the record as the warmest month. In July, the average heat index is evaluated at a very hot 95°F (35°C). Weather in July »Weather in August
The last month of the summer, August, is also a moderately hot month in Iona, South Dakota, with an average temperature ranging between max 85.8°F (29.9°C) and min 63.7°F (17.6°C). The transition into August marks the average high-temperature at a moderately hot 85.8°F (29.9°C), differing minimally from July's 88°F (31.1°C). Weather in August »Weather in September
The first month of the autumn, September, is also a moderately hot month in Iona, South Dakota, with temperature in the range of an average low of 55.9°F (13.3°C) and an average high of 76.3°F (24.6°C). September ushers in a slight temperature change, with average high-temperatures reducing from August's moderately hot 85.8°F (29.9°C) to a still warm 76.3°F (24.6°C). Weather in September »Weather in October
October, the same as September, in Iona, South Dakota, is another refreshing autumn month, with temperature in the range of an average low of 42.4°F (5.8°C) and an average high of 58.6°F (14.8°C). Iona in October experiences a marked decrease in the average high-temperature, descending from September's warm 76.3°F (24.6°C) to a mild 58.6°F (14.8°C). Weather in October »Weather in November
The last month of the autumn, November, is another chilly month in Iona, South Dakota, with an average temperature varying between 45.5°F (7.5°C) and 29.7°F (-1.3°C). November's onset brings a reduction in the average high-temperature, from a mild 58.6°F (14.8°C) in October to a chilly 45.5°F (7.5°C). Weather in November »Weather in December
The first month of the winter, December, is still a freezing cold month in Iona, South Dakota, with temperature in the range of an average high of 29.1°F (-1.6°C) and an average low of 16.9°F (-8.4°C). Iona sees a considerable decrease in average high-temperatures during December, falling from a chilly 45.5°F (7.5°C) in November to a subzero cold 29.1°F (-1.6°C). Weather in December »Updated: Jun 24, 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 stands out as Iona's coldest month, with temperatures ranging between an average high of 26.1°F (-3.3°C) and a low of 12.6°F (-10.8°C).
With an average relative humidity of 86%, January is the most humid month in Iona.
Throughout the year, there are 107.6 rainfall days, and 17.83" (453mm) of precipitation is accumulated.
January through April, October through December are months with snowfall in Iona.
Throughout the year, there are 50.9 snowfall days, and 17.87" (454mm) of snow is accumulated.
The month with the least sunshine is January, with an average of 4.7h of sunshine.
February is the month with the most snowfall. Snow falls for 11.7 days and accumulates 3.66" (93mm) of snow.
With an average maximum UV index of 1, February is the month with the lowest UV index.
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 September are months without snowfall.
June is the month with the most rainfall. Rain falls for 14.6 days and accumulates 3.03" (77mm) of precipitation.
With an average of 15h and 24min of daylight, June has the longest days of the year.
June through August, with an average maximum UV index of 6, are months with the highest UV index.
The warmest period is July, when temperatures fluctuate between an average high of 88°F (31.1°C) and a low of 66.2°F (19°C).
The month with the most sunshine is July, with an average of 11.4h of sunshine.
With an average relative humidity of 58%, September is the least humid month.
The month with the least rainfall is November, when the rain falls for 4.1 days and typically collects 0.55" (14mm) of precipitation.
December has the shortest days of the year, with an average of 9h and 0min of daylight.
Average temperature
Iona, SD
The warmest month (with the highest average high temperature) is July (88°F).
The month with the lowest average high temperature is January (26.1°F).
The month with the highest average low temperature is July (66.2°F).
The coldest month (with the lowest average low temperature) is January (12.6°F).
Average pressure
Iona, SD
- Average pressure in January:
30.16"Hg - Average pressure in February:
30.15"Hg - Average pressure in March:
30.05"Hg - Average pressure in April:
29.93"Hg - Average pressure in May:
29.91"Hg - Average pressure in June:
29.84"Hg
- Average pressure in July:
29.91"Hg - Average pressure in August:
29.91"Hg - Average pressure in September:
29.95"Hg - Average pressure in October:
29.98"Hg - Average pressure in November:
30.06"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 (29.84"Hg).
Average wind speed
Iona, SD
- Average wind speed in January:
10.3mph - Average wind speed in February:
9.9mph - Average wind speed in March:
10.6mph - Average wind speed in April:
11.3mph - Average wind speed in May:
10.4mph - Average wind speed in June:
9.8mph
- Average wind speed in July:
9.2mph - Average wind speed in August:
9.1mph - Average wind speed in September:
10.3mph - Average wind speed in October:
10.7mph - Average wind speed in November:
10.1mph - Average wind speed in December:
10mph
The windiest month (with the highest average wind speed) is April (11.3mph).
The calmest month (with the lowest average wind speed) is August (9.1mph).
Average humidity
Iona, SD
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is September (58%).
Average rainfall
Iona, SD
- Average rainfall in January:
0.59" - Average rainfall in February:
0.67" - Average rainfall in March:
1.26" - Average rainfall in April:
1.89" - Average rainfall in May:
2.8" - Average rainfall in June:
3.03"
- Average rainfall in July:
2.28" - Average rainfall in August:
1.5" - Average rainfall in September:
1.18" - Average rainfall in October:
1.14" - Average rainfall in November:
0.55" - Average rainfall in December:
0.94"
The wettest month (with the highest rainfall) is June (3.03").
The driest month (with the least rainfall) is November (0.55").
Average rainfall days
Iona, SD
- Average rainfall days in January:
4.8 days - Average rainfall days in February:
3.3 days - Average rainfall days in March:
8.8 days - Average rainfall days in April:
13.7 days - Average rainfall days in May:
15.3 days - Average rainfall days in June:
14.6 days
- Average rainfall days in July:
11.8 days - Average rainfall days in August:
11 days - Average rainfall days in September:
8.5 days - Average rainfall days in October:
7.8 days - Average rainfall days in November:
4.1 days - Average rainfall days in December:
3.9 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is February (3.3 days).
Average snowfall
Iona, SD
The month with the highest snowfall is February (3.66").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Iona, SD
- Average snowfall days in January:
11.7 days - Average snowfall days in February:
11.7 days - Average snowfall days in March:
8.3 days - Average snowfall days in April:
3.4 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:
1.6 days - Average snowfall days in November:
4.5 days - Average snowfall days in December:
9.6 days
The months with the highest number of snowfall days are January and February (11.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Iona, SD
- Average daylight in January:
9h and 24min - Average daylight in February:
10h and 30min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 30min - Average daylight in May:
14h and 42min - Average daylight in June:
15h and 24min
- 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 0min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in January:
4h and 42min - Average sunshine in February:
5h and 48min - Average sunshine in March:
6h and 48min - Average sunshine in April:
7h and 54min - Average sunshine in May:
9h and 30min - Average sunshine in June:
10h and 48min
- Average sunshine in July:
11h and 24min - Average sunshine in August:
11h and 0min - Average sunshine in September:
8h and 48min - Average sunshine in October:
6h and 48min - Average sunshine in November:
6h and 6min - Average sunshine in December:
4h and 54min
The month with the most sunshine is July (Average sunshine: 11h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 42min).
Average sunshine days
Iona, SD
- Average sunshine days in January:
17.8 days - Average sunshine days in February:
16.3 days - Average sunshine days in March:
14.8 days - Average sunshine days in April:
11.8 days - Average sunshine days in May:
12.1 days - Average sunshine days in June:
12.4 days
- Average sunshine days in July:
15.9 days - Average sunshine days in August:
17.2 days - Average sunshine days in September:
19.6 days - Average sunshine days in October:
19.9 days - Average sunshine days in November:
20.7 days - Average sunshine days in December:
19.5 days
The month with the most sunshine days is November (20.7 days).
The month with the least sunshine days is April (11.8 days).
Average UV index
Iona, SD
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is February (UV index 1).
Average cloud cover
Iona, SD
The month with the most cloud cover is January (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 20).
Average visibility
Iona, SD
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).
