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Contents
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average snowfall
- Average snowfall days
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Weather in January
January, like December, is another subzero cold winter month in Union, Iowa, with an average temperature fluctuating between 24.4°F (-4.2°C) and 12.2°F (-11°C). In Union, the month of January registers the lowest temperatures, averaging 24.4°F (-4.2°C) at the peak and 12.2°F (-11°C) at the lowest. Weather in January »
Weather in February
February, the last month of the winter in Union, is another freezing cold month, with an average temperature fluctuating between 28.9°F (-1.7°C) and 15.8°F (-9°C). Transitioning into February, Union experiences an average high-temperature of a still freezing cold 28.9°F (-1.7°C), marking a minor shift from the preceding month. Weather in February »
Weather in March
The first month of the spring, March, is a chilly month in Union, Iowa, with temperature in the range of an average low of 29.7°F (-1.3°C) and an average high of 44.1°F (6.7°C). The average high-temperature exhibits a considerable increase in March, surging from a freezing cold 28.9°F (-1.7°C) in February to a chilly 44.1°F (6.7°C). Weather in March »
Weather in April
April is a refreshing spring month in Union, Iowa, with an average temperature varying between 40.8°F (4.9°C) and 56.8°F (13.8°C). Union's April weather shows an increase in high-temperatures, moving from March's frosty 44.1°F (6.7°C) to a moderate 56.8°F (13.8°C). Weather in April »
Weather in May
May, the last month of the spring in Union, is a pleasant month, with an average temperature varying between 68.4°F (20.2°C) and 52.2°F (11.2°C). Union sees an increase in the average high-temperature with the arrival of May, moving from April's refreshing 56.8°F (13.8°C) to an agreeable 68.4°F (20.2°C). Weather in May »
Weather in June
June, the first month of the summer in Union, is a warm month, with temperature in the range of an average low of 61.7°F (16.5°C) and an average high of 77.5°F (25.3°C). Union's weather shows a temperature rise with the arrival of June, moving from a pleasant 68.4°F (20.2°C) in May 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 Union, Iowa, with temperature in the range of an average high of 79.9°F (26.6°C) and an average low of 63.9°F (17.7°C). In Union, Iowa, July is the warmest month, with temperatures averaging a high of 79.9°F (26.6°C) and a low of 63.9°F (17.7°C). Weather in July »
Weather in August
August, the last month of the summer in Union, is another warm month, with an average temperature ranging between max 78.4°F (25.8°C) and min 60.8°F (16°C). August begins with an average high-temperature of a still warm 78.4°F (25.8°C), reflecting close similarity to the preceding month. Weather in August »
Weather in September
The first month of the autumn, September, is also a moderately hot month in Union, Iowa, with an average temperature ranging between min 54.5°F (12.5°C) and max 73.8°F (23.2°C). Union experiences a subtle adjustment in high-temperatures to a still warm 73.8°F (23.2°C) with the onset of September, maintaining near parity with August's 78.4°F (25.8°C). Weather in September »
Weather in October
October, like September, is another refreshing autumn month in Union, Iowa, with an average temperature ranging between max 58.5°F (14.7°C) and min 43.7°F (6.5°C). A clear reduction in the average high-temperature is witnessed with the onset of October, reducing from a moderately hot 73.8°F (23.2°C) in September to a refreshing 58.5°F (14.7°C). Weather in October »
Weather in November
November, the last month of the autumn in Union, is also a frosty month, with an average temperature fluctuating between 44.4°F (6.9°C) and 31.3°F (-0.4°C). A moderate decline in the average high-temperature is seen during November, decreasing from a moderate 58.5°F (14.7°C) in October to a chilly 44.4°F (6.9°C). Weather in November »
Weather in December
December, the first month of the winter in Union, is still a freezing cold month, with temperature in the range of an average low of 20.1°F (-6.6°C) and an average high of 30.9°F (-0.6°C). The onset of December comes with a shift in the average high-temperature, falling from a frosty 44.4°F (6.9°C) in November to a freezing cold 30.9°F (-0.6°C). Weather in December »
Updated: Jul 4, 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
What part of the year is the coldest?
January is the coldest month, with an average high-temperature of 24.4°F (-4.2°C) and an average low-temperature of 12.2°F (-11°C).
What is the most humid month?
The most humid month is January, with an average relative humidity of 87%.
What is the driest month?
The months with the least rainfall are January and February Rain falls for 2 days and accumulates 0.24" (6mm) of rain.
How much does it rain?
In Union, during the entire year, the rain falls for 83.5 days and collects up to 6.5" (165mm) of precipitation.
When does it snow?
Months with snowfall are January through April, October through December.
How much does it snow?
In Union, Iowa, during the entire year, snow falls for 26.6 days and aggregates up to 3.03" (77mm) of snow.
What is the month with the least sunshine?
January has the least sunshine of the year, with an average of 3.9h of sunshine.
When is the lowest UV index?
January, February, October through December, with an average maximum UV index of 2, are months with the lowest UV index.
When does it snow the most?
February is the month with the most snowfall in Union. Snow falls for 6.3 days and accumulates 0.79" (20mm) of snow.
When is Daylight Saving Time (DST)?
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.
What is the wettest month?
The month with the most rainfall is May, when the rain falls for 11.6 days and typically aggregates up to 1.06" (27mm) of precipitation.
When it does not snow?
May through September are months without snowfall in Union.
When are the longest days?
The month with the longest days is June, with an average of 15h and 12min of daylight.
When is the highest UV index?
June and July, with an average maximum UV index of 6, are months with the highest UV index.
What time of the year is the hottest?
In Union, temperatures reach their average annual highs in July, measuring 79.9°F (26.6°C) and a minimum average of 63.9°F (17.7°C).
What month has the most sunshine?
With an average of 10h of sunshine, July has the most sunshine of the year in Union.
What is the least humid month?
October is the least humid month, with an average relative humidity of 71%.
What is the month with the shortest days?
December has the shortest days of the year, with an average of 9h and 12min of daylight.
Average temperature
Union, IA
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (24.4°F).
The month with the highest average low temperature is July (63.9°F).
The coldest month (with the lowest average low temperature) is January (12.2°F).
Average pressure
Union, 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:
29.89"Hg
- Average pressure in July:
29.96"Hg - Average pressure in August:
29.97"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
30"Hg - Average pressure in November:
30.08"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 (29.89"Hg).
Average wind speed
Union, IA
- Average wind speed in January:
10.8mph - Average wind speed in February:
10.7mph - Average wind speed in March:
10.6mph - Average wind speed in April:
10.9mph - Average wind speed in May:
9.3mph - Average wind speed in June:
8.3mph
- Average wind speed in July:
7.1mph - Average wind speed in August:
7.1mph - Average wind speed in September:
8.4mph - Average wind speed in October:
9.9mph - Average wind speed in November:
10.6mph - Average wind speed in December:
10.3mph
The windiest month (with the highest average wind speed) is April (10.9mph).
The calmest months (with the lowest average wind speed) are July and August (7.1mph).
Average humidity
Union, IA
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (71%).
Average rainfall
Union, IA
- Average rainfall in January:
0.24" - Average rainfall in February:
0.24" - Average rainfall in March:
0.35" - Average rainfall in April:
0.67" - Average rainfall in May:
1.06" - Average rainfall in June:
0.91"
- Average rainfall in July:
0.75" - Average rainfall in August:
0.51" - Average rainfall in September:
0.51" - Average rainfall in October:
0.63" - Average rainfall in November:
0.35" - Average rainfall in December:
0.28"
The wettest month (with the highest rainfall) is May (1.06").
The driest months (with the least rainfall) are January and February (0.24").
Average rainfall days
Union, IA
- Average rainfall days in January:
2 days - Average rainfall days in February:
2 days - Average rainfall days in March:
7.8 days - Average rainfall days in April:
9.5 days - Average rainfall days in May:
11.6 days - Average rainfall days in June:
10.4 days
- Average rainfall days in July:
11.3 days - Average rainfall days in August:
8.3 days - Average rainfall days in September:
8.1 days - Average rainfall days in October:
5.5 days - Average rainfall days in November:
4 days - Average rainfall days in December:
3 days
The month with the highest number of rainy days is May (11.6 days).
The months with the least rainy days are January and February (2 days).
Average snowfall
Union, IA
The month with the highest snowfall is February (0.79").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Union, IA
- Average snowfall days in January:
7 days - Average snowfall days in February:
6.3 days - Average snowfall days in March:
3.8 days - Average snowfall days in April:
0.8 days - Average snowfall days in May:
0.2 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 days - Average snowfall days in November:
2.6 days - Average snowfall days in December:
4.9 days
The month with the highest number of snowfall days is January (7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Union, IA
- Average daylight in January:
9h and 3min - Average daylight in February:
10h and 4min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 2min - Average daylight in May:
14h and 4min - Average daylight in June:
15h and 1min
- Average daylight in July:
14h and 5min - Average daylight in August:
13h and 5min - Average daylight in September:
12h and 3min - Average daylight in October:
11h and 1min - Average daylight in November:
9h and 5min - Average daylight in December:
9h and 1min
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:
3h and 5min - Average sunshine in February:
4h and 2min - Average sunshine in March:
6h and 0min - Average sunshine in April:
7h and 4min - Average sunshine in May:
8h and 3min - Average sunshine in June:
9h and 4min
- Average sunshine in July:
10h and 0min - Average sunshine in August:
9h and 5min - Average sunshine in September:
9h and 2min - Average sunshine in October:
5h and 3min - Average sunshine in November:
5h and 2min - Average sunshine in December:
4h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days
Union, IA
- Average sunshine days in January:
25.2 days - Average sunshine days in February:
21.5 days - Average sunshine days in March:
21.1 days - Average sunshine days in April:
17.8 days - Average sunshine days in May:
16.3 days - Average sunshine days in June:
15.8 days
- Average sunshine days in July:
16.4 days - Average sunshine days in August:
19.6 days - Average sunshine days in September:
20.3 days - Average sunshine days in October:
23.5 days - Average sunshine days in November:
23 days - Average sunshine days in December:
24.6 days
The month with the most sunshine days is January (25.2 days).
The month with the least sunshine days is June (15.8 days).
Average UV index
Union, IA
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover
Union, IA
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 31).
Average visibility
Union, IA
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Union, Iowa, USA
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